Merge branch 'pr/374'

Encoding issues

src/com/fsck/k9/activity/MessageCompose.java

@@ -78,10 +78,11 @@ import com.fsck.k9.mail.internet.MimeMessage;
 import com.fsck.k9.mail.internet.MimeMultipart;
 import com.fsck.k9.mail.internet.MimeUtility;
 import com.fsck.k9.mail.internet.TextBody;
-import com.fsck.k9.mail.store.LocalStore;
 import com.fsck.k9.mail.store.LocalStore.LocalAttachmentBody;
+import com.fsck.k9.mail.store.LocalStore.LocalAttachmentMessageBody;
 import com.fsck.k9.view.MessageWebView;
 import org.apache.james.mime4j.codec.EncoderUtil;
+import org.apache.james.mime4j.util.MimeUtil;
 import org.htmlcleaner.CleanerProperties;
 import org.htmlcleaner.HtmlCleaner;
 import org.htmlcleaner.SimpleHtmlSerializer;
@@ -1471,11 +1472,17 @@ public class MessageCompose extends K9Activity implements OnClickListener {
      * @throws MessagingException
      */
     private void addAttachmentsToMessage(final MimeMultipart mp) throws MessagingException {
+        LocalAttachmentBody body;
         for (int i = 0, count = mAttachments.getChildCount(); i < count; i++) {
             Attachment attachment = (Attachment) mAttachments.getChildAt(i).getTag();
-
-            MimeBodyPart bp = new MimeBodyPart(
-                new LocalStore.LocalAttachmentBody(attachment.uri, getApplication()));
+            String contentType = attachment.contentType;
+            if (MimeUtil.isMessage(contentType)) {
+                body = new LocalAttachmentMessageBody(attachment.uri,
+                        getApplication());
+            } else {
+                body = new LocalAttachmentBody(attachment.uri, getApplication());
+            }
+            MimeBodyPart bp = new MimeBodyPart(body);
 
             /*
              * Correctly encode the filename here. Otherwise the whole
@@ -1483,11 +1490,11 @@ public class MessageCompose extends K9Activity implements OnClickListener {
              * MimeHeader.writeTo().
              */
             bp.addHeader(MimeHeader.HEADER_CONTENT_TYPE, String.format("%s;\n name=\"%s\"",
-                         attachment.contentType,
+                         contentType,
                          EncoderUtil.encodeIfNecessary(attachment.name,
                                  EncoderUtil.Usage.WORD_ENTITY, 7)));
 
-            bp.addHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, "base64");
+            bp.setEncoding(MimeUtility.getEncodingforType(contentType));
 
             /*
              * TODO: Oh the joys of MIME...

src/com/fsck/k9/mail/Body.java

@@ -5,7 +5,10 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
+import com.fsck.k9.mail.store.UnavailableStorageException;
+
 public interface Body {
     public InputStream getInputStream() throws MessagingException;
+    public void setEncoding(String encoding) throws UnavailableStorageException, MessagingException;
     public void writeTo(OutputStream out) throws IOException, MessagingException;
 }

src/com/fsck/k9/mail/BodyPart.java

@@ -11,4 +11,8 @@ public abstract class BodyPart implements Part {
     public void setParent(Multipart parent) {
         mParent = parent;
     }
+
+    public abstract void setEncoding(String encoding) throws MessagingException;
+
+    public abstract void setUsing7bitTransport() throws MessagingException;
 }

src/com/fsck/k9/mail/CompositeBody.java

@@ -0,0 +1,29 @@
+package com.fsck.k9.mail;
+
+
+/**
+ * A CompositeBody is a {@link Body} extension that can contain subparts that
+ * may require recursing through or iterating over when converting the
+ * CompositeBody from 8bit to 7bit encoding. The {@link Part} to which a
+ * CompositeBody belongs is only permitted to use 8bit or 7bit content transfer
+ * encoding for the CompositeBody.
+ *
+ */
+public interface CompositeBody extends Body {
+
+    /**
+     * Called just prior to transmission, once the type of transport is known to
+     * be 7bit.
+     * <p>
+     * All subparts that are 8bit and of type {@link CompositeBody} will be
+     * converted to 7bit and recursed. All supbparts that are 8bit but not
+     * of type CompositeBody will be converted to quoted-printable. Bodies with
+     * encodings other than 8bit remain unchanged.
+     *
+     * @throws MessagingException
+     *
+     */
+
+    public abstract void setUsing7bitTransport() throws MessagingException;
+
+}

src/com/fsck/k9/mail/Message.java

@@ -15,7 +15,7 @@ import com.fsck.k9.mail.filter.EOLConvertingOutputStream;
 import com.fsck.k9.mail.store.UnavailableStorageException;
 
 
-public abstract class Message implements Part, Body {
+public abstract class Message implements Part, CompositeBody {
     private static final Flag[] EMPTY_FLAG_ARRAY = new Flag[0];
 
     private MessageReference mReference = null;
@@ -139,10 +139,6 @@ public abstract class Message implements Part, Body {
 
     public abstract void setBody(Body body) throws MessagingException;
 
-    public boolean isMimeType(String mimeType) throws MessagingException {
-        return getContentType().startsWith(mimeType);
-    }
-
     public abstract long getId();
 
     public abstract String getPreview();
@@ -240,7 +236,7 @@ public abstract class Message implements Part, Body {
 
     public void destroy() throws MessagingException {}
 
-    public abstract void setEncoding(String encoding) throws UnavailableStorageException;
+    public abstract void setEncoding(String encoding) throws UnavailableStorageException, MessagingException;
 
     public abstract void setCharset(String charset) throws MessagingException;
 
@@ -298,4 +294,5 @@ public abstract class Message implements Part, Body {
      * </p>
      */
     public abstract Message clone();
+    public abstract void setUsing7bitTransport() throws MessagingException;
 }

src/com/fsck/k9/mail/Multipart.java

@@ -3,11 +3,12 @@ package com.fsck.k9.mail;
 
 import java.util.ArrayList;
 
-import com.fsck.k9.mail.internet.MimeHeader;
+import org.apache.james.mime4j.util.MimeUtil;
+
 import com.fsck.k9.mail.internet.MimeUtility;
 import com.fsck.k9.mail.internet.TextBody;
 
-public abstract class Multipart implements Body {
+public abstract class Multipart implements CompositeBody {
     protected Part mParent;
 
     protected ArrayList<BodyPart> mParts = new ArrayList<BodyPart>();
@@ -54,19 +55,14 @@ public abstract class Multipart implements Body {
         this.mParent = parent;
     }
 
-    public void setEncoding(String encoding) {
-        for (BodyPart part : mParts) {
-            try {
-                Body body = part.getBody();
-                if (body instanceof TextBody) {
-                    part.setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, encoding);
-                    ((TextBody)body).setEncoding(encoding);
-                }
-            } catch (MessagingException e) {
-                // Ignore
-            }
+    public void setEncoding(String encoding) throws MessagingException {
+        if (!MimeUtil.ENC_7BIT.equalsIgnoreCase(encoding)
+                && !MimeUtil.ENC_8BIT.equalsIgnoreCase(encoding)) {
+            throw new MessagingException(
+                    "Incompatible content-transfer-encoding applied to a CompositeBody");
         }
 
+        /* Nothing else to do.  Each subpart has its own separate encoding */
     }
 
     public void setCharset(String charset) throws MessagingException {

src/com/fsck/k9/mail/Part.java

@@ -30,4 +30,17 @@ public interface Part {
     public void setBody(Body body) throws MessagingException;
 
     public void writeTo(OutputStream out) throws IOException, MessagingException;
+
+    /**
+     * Called just prior to transmission, once the type of transport is known to
+     * be 7bit.
+     * <p>
+     * All bodies that are 8bit will be converted to 7bit and recursed if of
+     * type {@link CompositeBody}, or will be converted to quoted-printable in all other
+     * cases. Bodies with encodings other than 8bit remain unchanged.
+     *
+     * @throws MessagingException
+     *
+     */
+    public abstract void setUsing7bitTransport() throws MessagingException;
 }

src/com/fsck/k9/mail/internet/BinaryTempFileBody.java

@@ -4,6 +4,8 @@ import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.MessagingException;
 import com.fsck.k9.mail.filter.Base64OutputStream;
 import org.apache.commons.io.IOUtils;
+import org.apache.james.mime4j.codec.QuotedPrintableOutputStream;
+import org.apache.james.mime4j.util.MimeUtil;
 
 import java.io.*;
 
@@ -18,10 +20,16 @@ public class BinaryTempFileBody implements Body {
 
     private File mFile;
 
+    String mEncoding = null;
+
     public static void setTempDirectory(File tempDirectory) {
         mTempDirectory = tempDirectory;
     }
 
+    public void setEncoding(String encoding) throws MessagingException {
+        mEncoding  = encoding;
+    }
+
     public BinaryTempFileBody() {
         if (mTempDirectory == null) {
             throw new
@@ -46,11 +54,21 @@ public class BinaryTempFileBody implements Body {
     public void writeTo(OutputStream out) throws IOException, MessagingException {
         InputStream in = getInputStream();
         try {
-            Base64OutputStream base64Out = new Base64OutputStream(out);
+            boolean closeStream = false;
+            if (MimeUtil.isBase64Encoding(mEncoding)) {
+                out = new Base64OutputStream(out);
+                closeStream = true;
+            } else if (MimeUtil.isQuotedPrintableEncoded(mEncoding)){
+                out = new QuotedPrintableOutputStream(out, false);
+                closeStream = true;
+            }
+
             try {
-                IOUtils.copy(in, base64Out);
+                IOUtils.copy(in, out);
             } finally {
-                base64Out.close();
+                if (closeStream) {
+                    out.close();
+                }
             }
         } finally {
             in.close();

src/com/fsck/k9/mail/internet/BinaryTempFileMessageBody.java

@@ -0,0 +1,62 @@
+package com.fsck.k9.mail.internet;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.james.mime4j.util.MimeUtil;
+
+import com.fsck.k9.mail.CompositeBody;
+import com.fsck.k9.mail.MessagingException;
+
+/**
+ * A {@link BinaryTempFileBody} extension containing a body of type
+ * message/rfc822. This relates to a BinaryTempFileBody the same way that a
+ * {@link LocalAttachmentMessageBody} relates to a {@link LocalAttachmentBody}.
+ *
+ */
+public class BinaryTempFileMessageBody extends BinaryTempFileBody implements CompositeBody {
+
+    @Override
+    public void setEncoding(String encoding) throws MessagingException {
+        if (!MimeUtil.ENC_7BIT.equalsIgnoreCase(encoding)
+                && !MimeUtil.ENC_8BIT.equalsIgnoreCase(encoding)) {
+            throw new MessagingException(
+                    "Incompatible content-transfer-encoding applied to a CompositeBody");
+        }
+        mEncoding = encoding;
+    }
+
+    @Override
+    public void writeTo(OutputStream out) throws IOException, MessagingException {
+        InputStream in = getInputStream();
+        try {
+            if (MimeUtil.ENC_7BIT.equalsIgnoreCase(mEncoding)) {
+                /*
+                 * If we knew the message was already 7bit clean, then it
+                 * could be sent along without processing. But since we
+                 * don't know, we recursively parse it.
+                 */
+                MimeMessage message = new MimeMessage(in, true);
+                message.setUsing7bitTransport();
+                message.writeTo(out);
+            } else {
+                IOUtils.copy(in, out);
+            }
+        } finally {
+            in.close();
+        }
+    }
+
+    @Override
+    public void setUsing7bitTransport() throws MessagingException {
+        /*
+         * There's nothing to recurse into here, so there's nothing to do.
+         * The enclosing BodyPart already called setEncoding(MimeUtil.ENC_7BIT).  Once
+         * writeTo() is called, the file with the rfc822 body will be opened
+         * for reading and will then be recursed.
+         */
+
+    }
+}

src/com/fsck/k9/mail/internet/MimeBodyPart.java

@@ -3,12 +3,17 @@ package com.fsck.k9.mail.internet;
 
 import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.BodyPart;
+import com.fsck.k9.mail.CompositeBody;
 import com.fsck.k9.mail.MessagingException;
+import com.fsck.k9.mail.Multipart;
 
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
+import java.util.Locale;
+
+import org.apache.james.mime4j.util.MimeUtil;
 
 /**
  * TODO this is a close approximation of Message, need to update along with
@@ -42,7 +47,7 @@ public class MimeBodyPart extends BodyPart {
         mHeader.addHeader(name, value);
     }
 
-    public void setHeader(String name, String value) throws MessagingException {
+    public void setHeader(String name, String value) {
         mHeader.setHeader(name, value);
     }
 
@@ -60,21 +65,35 @@ public class MimeBodyPart extends BodyPart {
 
     public void setBody(Body body) throws MessagingException {
         this.mBody = body;
-        if (body instanceof com.fsck.k9.mail.Multipart) {
-            com.fsck.k9.mail.Multipart multipart = ((com.fsck.k9.mail.Multipart)body);
+        if (body instanceof Multipart) {
+            Multipart multipart = ((Multipart)body);
             multipart.setParent(this);
-            setHeader(MimeHeader.HEADER_CONTENT_TYPE, multipart.getContentType());
+            String type = multipart.getContentType();
+            setHeader(MimeHeader.HEADER_CONTENT_TYPE, type);
+            if ("multipart/signed".equalsIgnoreCase(type)) {
+                setEncoding(MimeUtil.ENC_7BIT);
+            } else {
+                setEncoding(MimeUtil.ENC_8BIT);
+            }
         } else if (body instanceof TextBody) {
-            String contentType = String.format("%s;\n charset=utf-8", getMimeType());
+            String contentType = String.format("%s;\r\n charset=utf-8", getMimeType());
             String name = MimeUtility.getHeaderParameter(getContentType(), "name");
             if (name != null) {
-                contentType += String.format(";\n name=\"%s\"", name);
+                contentType += String.format(";\r\n name=\"%s\"", name);
             }
             setHeader(MimeHeader.HEADER_CONTENT_TYPE, contentType);
-            setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, "quoted-printable");
+            setEncoding(MimeUtil.ENC_8BIT);
         }
     }
 
+    @Override
+    public void setEncoding(String encoding) throws MessagingException {
+        if (mBody != null) {
+            mBody.setEncoding(encoding);
+        }
+        setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, encoding);
+    }
+
     public String getContentType() throws MessagingException {
         String contentType = getFirstHeader(MimeHeader.HEADER_CONTENT_TYPE);
         return (contentType == null) ? "text/plain" : contentType;
@@ -103,7 +122,7 @@ public class MimeBodyPart extends BodyPart {
     }
 
     public boolean isMimeType(String mimeType) throws MessagingException {
-        return getMimeType().equals(mimeType);
+        return getMimeType().equalsIgnoreCase(mimeType);
     }
 
     public int getSize() {
@@ -122,4 +141,46 @@ public class MimeBodyPart extends BodyPart {
             mBody.writeTo(out);
         }
     }
+
+    @Override
+    public void setUsing7bitTransport() throws MessagingException {
+        String type = getFirstHeader(MimeHeader.HEADER_CONTENT_TYPE);
+        /*
+         * We don't trust that a multipart/* will properly have an 8bit encoding
+         * header if any of its subparts are 8bit, so we automatically recurse
+         * (as long as its not multipart/signed).
+         */
+        if (mBody instanceof CompositeBody
+                && !"multipart/signed".equalsIgnoreCase(type)) {
+            setEncoding(MimeUtil.ENC_7BIT);
+            // recurse
+            ((CompositeBody) mBody).setUsing7bitTransport();
+        } else if (!MimeUtil.ENC_8BIT
+                .equalsIgnoreCase(getFirstHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING))) {
+            return;
+        } else if (type != null
+                && (type.equalsIgnoreCase("multipart/signed") || type
+                        .toLowerCase(Locale.US).startsWith("message/"))) {
+            /*
+             * This shouldn't happen. In any case, it would be wrong to convert
+             * them to some other encoding for 7bit transport.
+             *
+             * RFC 1847 says multipart/signed must be 7bit. It also says their
+             * bodies must be treated as opaque, so we must not change the
+             * encoding.
+             *
+             * We've dealt with (CompositeBody) type message/rfc822 above. Here
+             * we must deal with all other message/* types. RFC 2045 says
+             * message/* can only be 7bit or 8bit. RFC 2046 says unknown
+             * message/* types must be treated as application/octet-stream,
+             * which means we can't recurse into them. It also says that
+             * existing subtypes message/partial and message/external must only
+             * be 7bit, and that future subtypes "should be" 7bit.
+             */
+            throw new MessagingException(
+                    "Unable to convert 8bit body part to 7bit");
+        } else {
+            setEncoding(MimeUtil.ENC_QUOTED_PRINTABLE);
+        }
+    }
 }

src/com/fsck/k9/mail/internet/MimeMessage.java

@@ -22,10 +22,12 @@ import org.apache.james.mime4j.parser.MimeStreamParser;
 import org.apache.james.mime4j.stream.BodyDescriptor;
 import org.apache.james.mime4j.stream.Field;
 import org.apache.james.mime4j.stream.MimeConfig;
+import org.apache.james.mime4j.util.MimeUtil;
 
 import com.fsck.k9.mail.Address;
 import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.BodyPart;
+import com.fsck.k9.mail.CompositeBody;
 import com.fsck.k9.mail.Message;
 import com.fsck.k9.mail.MessagingException;
 import com.fsck.k9.mail.Multipart;
@@ -69,7 +71,23 @@ public class MimeMessage extends Message {
         parse(in);
     }
 
+    /**
+     * Parse the given InputStream using Apache Mime4J to build a MimeMessage.
+     *
+     * @param in
+     * @param recurse A boolean indicating to recurse through all nested MimeMessage subparts.
+     * @throws IOException
+     * @throws MessagingException
+     */
+    public MimeMessage(InputStream in, boolean recurse) throws IOException, MessagingException {
+        parse(in, true);
+    }
+
      protected void parse(InputStream in) throws IOException, MessagingException {
+        parse(in, false);
+    }
+
+    protected void parse(InputStream in, boolean recurse) throws IOException, MessagingException {
         mHeader.clear();
         mFrom = null;
         mTo = null;
@@ -92,6 +110,9 @@ public class MimeMessage extends Message {
         parserConfig.setMaxHeaderCount(-1); // Disable the check for header count.
         MimeStreamParser parser = new MimeStreamParser(parserConfig);
         parser.setContentHandler(new MimeMessageBuilder());
+        if (recurse) {
+            parser.setRecurse();
+        }
         try {
             parser.parse(new EOLConvertingInputStream(in));
         } catch (MimeException me) {
@@ -143,7 +164,7 @@ public class MimeMessage extends Message {
     @Override
     public String getContentType() throws MessagingException {
         String contentType = getFirstHeader(MimeHeader.HEADER_CONTENT_TYPE);
-        return (contentType == null) ? "text/plain" : contentType.toLowerCase(Locale.US);
+        return (contentType == null) ? "text/plain" : contentType;
     }
 
     public String getDisposition() throws MessagingException {
@@ -156,6 +177,10 @@ public class MimeMessage extends Message {
         return MimeUtility.getHeaderParameter(getContentType(), null);
     }
 
+    public boolean isMimeType(String mimeType) throws MessagingException {
+        return getMimeType().equalsIgnoreCase(mimeType);
+    }
+
     public int getSize() {
         return mSize;
     }
@@ -355,11 +380,17 @@ public class MimeMessage extends Message {
         if (body instanceof Multipart) {
             Multipart multipart = ((Multipart)body);
             multipart.setParent(this);
-            setHeader(MimeHeader.HEADER_CONTENT_TYPE, multipart.getContentType());
+            String type = multipart.getContentType();
+            setHeader(MimeHeader.HEADER_CONTENT_TYPE, type);
+            if ("multipart/signed".equalsIgnoreCase(type)) {
+                setEncoding(MimeUtil.ENC_7BIT);
+            } else {
+                setEncoding(MimeUtil.ENC_8BIT);
+            }
         } else if (body instanceof TextBody) {
-            setHeader(MimeHeader.HEADER_CONTENT_TYPE, String.format("%s;\n charset=utf-8",
+            setHeader(MimeHeader.HEADER_CONTENT_TYPE, String.format("%s;\r\n charset=utf-8",
                       getMimeType()));
-            setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, "quoted-printable");
+            setEncoding(MimeUtil.ENC_8BIT);
         }
     }
 
@@ -408,13 +439,11 @@ public class MimeMessage extends Message {
     }
 
     @Override
-    public void setEncoding(String encoding) throws UnavailableStorageException {
-        if (mBody instanceof Multipart) {
-            ((Multipart)mBody).setEncoding(encoding);
-        } else if (mBody instanceof TextBody) {
-            setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, encoding);
-            ((TextBody)mBody).setEncoding(encoding);
+    public void setEncoding(String encoding) throws MessagingException {
+        if (mBody != null) {
+            mBody.setEncoding(encoding);
         }
+        setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, encoding);
     }
 
     @Override
@@ -487,8 +516,9 @@ public class MimeMessage extends Message {
 
         public void body(BodyDescriptor bd, InputStream in) throws IOException {
             expect(Part.class);
-            Body body = MimeUtility.decodeBody(in, bd.getTransferEncoding());
             try {
+                Body body = MimeUtility.decodeBody(in,
+                        bd.getTransferEncoding(), bd.getMimeType());
                 ((Part)stack.peek()).setBody(body);
             } catch (MessagingException me) {
                 throw new Error(me);
@@ -597,4 +627,47 @@ public class MimeMessage extends Message {
     public boolean hasAttachments() {
         return false;
     }
+
+
+    @Override
+    public void setUsing7bitTransport() throws MessagingException {
+        String type = getFirstHeader(MimeHeader.HEADER_CONTENT_TYPE);
+        /*
+         * We don't trust that a multipart/* will properly have an 8bit encoding
+         * header if any of its subparts are 8bit, so we automatically recurse
+         * (as long as its not multipart/signed).
+         */
+        if (mBody instanceof CompositeBody
+                && !"multipart/signed".equalsIgnoreCase(type)) {
+            setEncoding(MimeUtil.ENC_7BIT);
+            // recurse
+            ((CompositeBody) mBody).setUsing7bitTransport();
+        } else if (!MimeUtil.ENC_8BIT
+                .equalsIgnoreCase(getFirstHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING))) {
+            return;
+        } else if (type != null
+                && (type.equalsIgnoreCase("multipart/signed") || type
+                        .toLowerCase(Locale.US).startsWith("message/"))) {
+            /*
+             * This shouldn't happen. In any case, it would be wrong to convert
+             * them to some other encoding for 7bit transport.
+             *
+             * RFC 1847 says multipart/signed must be 7bit. It also says their
+             * bodies must be treated as opaque, so we must not change the
+             * encoding.
+             *
+             * We've dealt with (CompositeBody) type message/rfc822 above. Here
+             * we must deal with all other message/* types. RFC 2045 says
+             * message/* can only be 7bit or 8bit. RFC 2046 says unknown
+             * message/* types must be treated as application/octet-stream,
+             * which means we can't recurse into them. It also says that
+             * existing subtypes message/partial and message/external must only
+             * be 7bit, and that future subtypes "should be" 7bit.
+             */
+            throw new MessagingException(
+                    "Unable to convert 8bit body part to 7bit");
+        } else {
+            setEncoding(MimeUtil.ENC_QUOTED_PRINTABLE);
+        }
+    }
 }

src/com/fsck/k9/mail/internet/MimeMultipart.java

@@ -99,4 +99,11 @@ public class MimeMultipart extends Multipart {
     public InputStream getInputStream() throws MessagingException {
         return null;
     }
+
+    @Override
+    public void setUsing7bitTransport() throws MessagingException {
+        for (BodyPart part : mParts) {
+            part.setUsing7bitTransport();
+        }
+    }
 }

src/com/fsck/k9/mail/internet/MimeUtility.java

@@ -13,6 +13,7 @@ import com.fsck.k9.mail.internet.BinaryTempFileBody.BinaryTempFileBodyInputStrea
 import org.apache.commons.io.IOUtils;
 import org.apache.james.mime4j.codec.Base64InputStream;
 import org.apache.james.mime4j.codec.QuotedPrintableInputStream;
+import org.apache.james.mime4j.util.MimeUtil;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -1155,23 +1156,31 @@ public class MimeUtility {
 
     /**
      * Removes any content transfer encoding from the stream and returns a Body.
+     * @throws MessagingException
      */
-    public static Body decodeBody(InputStream in, String contentTransferEncoding)
-    throws IOException {
+    public static Body decodeBody(InputStream in,
+            String contentTransferEncoding, String contentType)
+            throws IOException, MessagingException {
         /*
          * We'll remove any transfer encoding by wrapping the stream.
          */
         if (contentTransferEncoding != null) {
             contentTransferEncoding =
                 MimeUtility.getHeaderParameter(contentTransferEncoding, null);
-            if ("quoted-printable".equalsIgnoreCase(contentTransferEncoding)) {
+            if (MimeUtil.ENC_QUOTED_PRINTABLE.equalsIgnoreCase(contentTransferEncoding)) {
                 in = new QuotedPrintableInputStream(in);
-            } else if ("base64".equalsIgnoreCase(contentTransferEncoding)) {
+            } else if (MimeUtil.ENC_BASE64.equalsIgnoreCase(contentTransferEncoding)) {
                 in = new Base64InputStream(in);
             }
         }
 
-        BinaryTempFileBody tempBody = new BinaryTempFileBody();
+        BinaryTempFileBody tempBody;
+        if (MimeUtil.isMessage(contentType)) {
+            tempBody = new BinaryTempFileMessageBody();
+        } else {
+            tempBody = new BinaryTempFileBody();
+        }
+        tempBody.setEncoding(contentTransferEncoding);
         OutputStream out = tempBody.getOutputStream();
         try {
             IOUtils.copy(in, out);
@@ -2160,6 +2169,38 @@ public class MimeUtility {
         return canonicalizeMimeType(mimeType);
     }
 
+
+    /**
+     * Get a default content-transfer-encoding for use with a given content-type
+     * when adding an unencoded attachment. It's possible that 8bit encodings
+     * may later be converted to 7bit for 7bit transport.
+     * <ul>
+     * <li>null: base64
+     * <li>message/rfc822: 8bit
+     * <li>message/*: 7bit
+     * <li>multipart/signed: 7bit
+     * <li>multipart/*: 8bit
+     * <li>*&#47;*: base64
+     * </ul>
+     *
+     * @param type
+     *            A String representing a MIME content-type
+     * @return A String representing a MIME content-transfer-encoding
+     */
+    public static String getEncodingforType(String type) {
+        if (type == null) {
+            return (MimeUtil.ENC_BASE64);
+        } else if (MimeUtil.isMessage(type)) {
+            return (MimeUtil.ENC_8BIT);
+        } else if ("multipart/signed".equalsIgnoreCase(type) || type.toLowerCase(Locale.US).startsWith("message/")) {
+            return (MimeUtil.ENC_7BIT);
+        } else if (type.toLowerCase(Locale.US).startsWith("multipart/")) {
+            return (MimeUtil.ENC_8BIT);
+        } else {
+            return (MimeUtil.ENC_BASE64);
+        }
+    }
+
     private static Message getMessageFromPart(Part part) {
         while (part != null) {
             if (part instanceof Message)
@@ -3326,7 +3367,7 @@ public class MimeUtility {
 
     public static void setCharset(String charset, Part part) throws MessagingException {
         part.setHeader(MimeHeader.HEADER_CONTENT_TYPE,
-                       part.getMimeType() + ";\n charset=" + getExternalCharset(charset));
+                       part.getMimeType() + ";\r\n charset=" + getExternalCharset(charset));
     }
 
     public static String getExternalCharset(String charset) {

src/com/fsck/k9/mail/internet/TextBody.java

@@ -7,6 +7,7 @@ import com.fsck.k9.mail.MessagingException;
 import java.io.*;
 
 import org.apache.james.mime4j.codec.QuotedPrintableOutputStream;
+import org.apache.james.mime4j.util.MimeUtil;
 
 public class TextBody implements Body {
 
@@ -31,7 +32,7 @@ public class TextBody implements Body {
     public void writeTo(OutputStream out) throws IOException, MessagingException {
         if (mBody != null) {
             byte[] bytes = mBody.getBytes(mCharset);
-            if ("8bit".equals(mEncoding)) {
+            if (MimeUtil.ENC_8BIT.equalsIgnoreCase(mEncoding)) {
                 out.write(bytes);
             } else {
                 QuotedPrintableOutputStream qp = new QuotedPrintableOutputStream(out, false);

src/com/fsck/k9/mail/store/ImapStore.java

@@ -1653,9 +1653,12 @@ public class ImapStore extends Store {
                                 String bodyString = (String)literal;
                                 InputStream bodyStream = new ByteArrayInputStream(bodyString.getBytes());
 
-                                String contentTransferEncoding = part.getHeader(
-                                                                     MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING)[0];
-                                part.setBody(MimeUtility.decodeBody(bodyStream, contentTransferEncoding));
+                                String contentTransferEncoding = part
+                                        .getHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING)[0];
+                                String contentType = part
+                                        .getHeader(MimeHeader.HEADER_CONTENT_TYPE)[0];
+                                part.setBody(MimeUtility.decodeBody(bodyStream,
+                                        contentTransferEncoding, contentType));
                             } else {
                                 // This shouldn't happen
                                 throw new MessagingException("Got FETCH response with bogus parameters");
@@ -3547,10 +3550,13 @@ public class ImapStore extends Store {
                     ImapResponseParser.equalsIgnoreCase(response.get(1), "FETCH")) {
                 //TODO: check for correct UID
 
-                String contentTransferEncoding = mPart.getHeader(
-                                                     MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING)[0];
+                String contentTransferEncoding = mPart
+                        .getHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING)[0];
+                String contentType = mPart
+                        .getHeader(MimeHeader.HEADER_CONTENT_TYPE)[0];
 
-                return MimeUtility.decodeBody(literal, contentTransferEncoding);
+                return MimeUtility.decodeBody(literal, contentTransferEncoding,
+                        contentType);
             }
             return null;
         }

src/com/fsck/k9/mail/store/LocalStore.java

@@ -25,6 +25,8 @@ import java.util.UUID;
 import java.util.regex.Pattern;
 
 import org.apache.commons.io.IOUtils;
+import org.apache.james.mime4j.codec.QuotedPrintableOutputStream;
+import org.apache.james.mime4j.util.MimeUtil;
 
 import android.app.Application;
 import android.content.ContentResolver;
@@ -51,6 +53,7 @@ import com.fsck.k9.helper.Utility;
 import com.fsck.k9.mail.Address;
 import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.BodyPart;
+import com.fsck.k9.mail.CompositeBody;
 import com.fsck.k9.mail.FetchProfile;
 import com.fsck.k9.mail.Flag;
 import com.fsck.k9.mail.Folder;
@@ -1936,6 +1939,7 @@ public class LocalStore extends Store implements Serializable {
                                             String contentUri = cursor.getString(5);
                                             String contentId = cursor.getString(6);
                                             String contentDisposition = cursor.getString(7);
+                                            String encoding = MimeUtility.getEncodingforType(type);
                                             Body body = null;
 
                                             if (contentDisposition == null) {
@@ -1943,11 +1947,19 @@ public class LocalStore extends Store implements Serializable {
                                             }
 
                                             if (contentUri != null) {
-                                                body = new LocalAttachmentBody(Uri.parse(contentUri), mApplication);
+                                                if (MimeUtil.isMessage(type)) {
+                                                    body = new LocalAttachmentMessageBody(
+                                                            Uri.parse(contentUri),
+                                                            mApplication);
+                                                } else {
+                                                    body = new LocalAttachmentBody(
+                                                            Uri.parse(contentUri),
+                                                            mApplication);
+                                                }
                                             }
 
                                             MimeBodyPart bp = new LocalAttachmentBodyPart(body, id);
-                                            bp.setHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, "base64");
+                                            bp.setEncoding(encoding);
                                             if (name != null) {
                                                 bp.setHeader(MimeHeader.HEADER_CONTENT_TYPE,
                                                              String.format("%s;\n name=\"%s\"",
@@ -2852,7 +2864,13 @@ public class LocalStore extends Store implements Serializable {
                                 contentUri = AttachmentProvider.getAttachmentUri(
                                                  mAccount,
                                                  attachmentId);
-                                attachment.setBody(new LocalAttachmentBody(contentUri, mApplication));
+                                if (MimeUtil.isMessage(attachment.getMimeType())) {
+                                    attachment.setBody(new LocalAttachmentMessageBody(
+                                            contentUri, mApplication));
+                                } else {
+                                    attachment.setBody(new LocalAttachmentBody(
+                                            contentUri, mApplication));
+                                }
                                 ContentValues cv = new ContentValues();
                                 cv.put("content_uri", contentUri != null ? contentUri.toString() : null);
                                 db.update("attachments", cv, "id = ?", new String[]
@@ -3988,6 +4006,7 @@ public class LocalStore extends Store implements Serializable {
         private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
         private Application mApplication;
         private Uri mUri;
+        protected String mEncoding;
 
         public LocalAttachmentBody(Uri uri, Application application) {
             mApplication = application;
@@ -4011,11 +4030,21 @@ public class LocalStore extends Store implements Serializable {
         public void writeTo(OutputStream out) throws IOException, MessagingException {
             InputStream in = getInputStream();
             try {
-                Base64OutputStream base64Out = new Base64OutputStream(out);
+                boolean closeStream = false;
+                if (MimeUtil.isBase64Encoding(mEncoding)) {
+                    out = new Base64OutputStream(out);
+                    closeStream = true;
+                } else if (MimeUtil.isQuotedPrintableEncoded(mEncoding)){
+                    out = new QuotedPrintableOutputStream(out, false);
+                    closeStream = true;
+                }
+
                 try {
-                    IOUtils.copy(in, base64Out);
+                    IOUtils.copy(in, out);
                 } finally {
-                    base64Out.close();
+                    if (closeStream) {
+                        out.close();
+                    }
                 }
             } finally {
                 in.close();
@@ -4025,6 +4054,64 @@ public class LocalStore extends Store implements Serializable {
         public Uri getContentUri() {
             return mUri;
         }
+
+        public void setEncoding(String encoding) throws MessagingException {
+            mEncoding = encoding;
+        }
+    }
+
+    /**
+     * A {@link LocalAttachmentBody} extension containing a message/rfc822 type body
+     *
+     */
+    public static class LocalAttachmentMessageBody extends LocalAttachmentBody implements CompositeBody {
+
+        public LocalAttachmentMessageBody(Uri uri, Application application) {
+            super(uri, application);
+        }
+
+        @Override
+        public void writeTo(OutputStream out) throws IOException,
+                MessagingException {
+            InputStream in = getInputStream();
+            try {
+                if (MimeUtil.ENC_7BIT.equalsIgnoreCase(mEncoding)) {
+                    /*
+                     * If we knew the message was already 7bit clean, then it
+                     * could be sent along without processing. But since we
+                     * don't know, we recursively parse it.
+                     */
+                    MimeMessage message = new MimeMessage(in, true);
+                    message.setUsing7bitTransport();
+                    message.writeTo(out);
+                } else {
+                    IOUtils.copy(in, out);
+                }
+            } finally {
+                in.close();
+            }
+        }
+
+        @Override
+        public void setUsing7bitTransport() throws MessagingException {
+            /*
+             * There's nothing to recurse into here, so there's nothing to do.
+             * The enclosing BodyPart already called setEncoding(MimeUtil.ENC_7BIT).  Once
+             * writeTo() is called, the file with the rfc822 body will be opened
+             * for reading and will then be recursed.
+             */
+
+        }
+
+        @Override
+        public void setEncoding(String encoding) throws MessagingException {
+            if (!MimeUtil.ENC_7BIT.equalsIgnoreCase(encoding)
+                    && !MimeUtil.ENC_8BIT.equalsIgnoreCase(encoding)) {
+                throw new MessagingException(
+                        "Incompatible content-transfer-encoding applied to a CompositeBody");
+            }
+            mEncoding = encoding;
+        }
     }
 
     static class ThreadInfo {

src/com/fsck/k9/mail/transport/SmtpTransport.java

@@ -477,7 +477,9 @@ public class SmtpTransport extends Transport {
         close();
         open();
 
-        message.setEncoding(m8bitEncodingAllowed ? "8bit" : null);
+        if (!m8bitEncodingAllowed) {
+            message.setUsing7bitTransport();
+        }
         // If the message has attachments and our server has told us about a limit on
         // the size of messages, count the message's size before sending it
         if (mLargestAcceptableMessage > 0 && ((LocalMessage)message).hasAttachments()) {
@@ -490,8 +492,8 @@ public class SmtpTransport extends Transport {
 
         Address[] from = message.getFrom();
         try {
-            //TODO: Add BODY=8BITMIME parameter if appropriate?
-            executeSimpleCommand("MAIL FROM:" + "<" + from[0].getAddress() + ">");
+            executeSimpleCommand("MAIL FROM:" + "<" + from[0].getAddress() + ">"
+                    + (m8bitEncodingAllowed ? " BODY=8BITMIME" : ""));
             for (String address : addresses) {
                 executeSimpleCommand("RCPT TO:" + "<" + address + ">");
             }

tests/src/com/fsck/k9/mail/MessageTest.java

@@ -0,0 +1,380 @@
+package com.fsck.k9.mail;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import org.apache.commons.io.IOUtils;
+import org.apache.james.mime4j.codec.Base64InputStream;
+import org.apache.james.mime4j.util.MimeUtil;
+
+import android.test.AndroidTestCase;
+
+import com.fsck.k9.mail.Message.RecipientType;
+import com.fsck.k9.mail.internet.BinaryTempFileBody;
+import com.fsck.k9.mail.internet.BinaryTempFileMessageBody;
+import com.fsck.k9.mail.internet.MimeBodyPart;
+import com.fsck.k9.mail.internet.MimeHeader;
+import com.fsck.k9.mail.internet.MimeMessage;
+import com.fsck.k9.mail.internet.MimeMultipart;
+import com.fsck.k9.mail.internet.MimeUtility;
+import com.fsck.k9.mail.internet.TextBody;
+
+public class MessageTest extends AndroidTestCase {
+
+    private static final String EIGHT_BIT_RESULT =
+              "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary103\"\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "Testing.\r\n"
+            + "This is a text body with some greek characters.\r\n"
+            + "αβγδεζηθ\r\n"
+            + "End of test.\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: message/rfc822\r\n"
+            + "Content-Disposition: attachment\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary102\"\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "Testing.\r\n"
+            + "This is a text body with some greek characters.\r\n"
+            + "αβγδεζηθ\r\n"
+            + "End of test.\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: message/rfc822\r\n"
+            + "Content-Disposition: attachment\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary101\"\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: 8bit\r\n"
+            + "\r\n"
+            + "Testing.\r\n"
+            + "This is a text body with some greek characters.\r\n"
+            + "αβγδεζηθ\r\n"
+            + "End of test.\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary101--\r\n"
+            + "\r\n"
+            + "------Boundary102--\r\n"
+            + "\r\n"
+            + "------Boundary103--\r\n";
+
+    private static final String SEVEN_BIT_RESULT =
+              "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary103\"\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: text/plain;\r\n"
+            + " charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary103\r\n"
+            + "Content-Type: message/rfc822\r\n"
+            + "Content-Disposition: attachment\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n"
+            + "\r\n"
+            + "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary102\"\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: text/plain; charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: text/plain; charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary102\r\n"
+            + "Content-Type: message/rfc822\r\n"
+            + "Content-Disposition: attachment\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n"
+            + "\r\n"
+            + "From: from@example.com\r\n"
+            + "To: to@example.com\r\n"
+            + "Subject: Test Message\r\n"
+            + "Date: Wed, 28 Aug 2013 08:51:09 -0400\r\n"
+            + "MIME-Version: 1.0\r\n"
+            + "Content-Type: multipart/mixed; boundary=\"----Boundary101\"\r\n"
+            + "Content-Transfer-Encoding: 7bit\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: text/plain; charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: text/plain; charset=utf-8\r\n"
+            + "Content-Transfer-Encoding: quoted-printable\r\n"
+            + "\r\n"
+            + "Testing=2E\r\n"
+            + "This is a text body with some greek characters=2E\r\n"
+            + "=CE=B1=CE=B2=CE=B3=CE=B4=CE=B5=CE=B6=CE=B7=CE=B8\r\n"
+            + "End of test=2E\r\n"
+            + "\r\n"
+            + "------Boundary101\r\n"
+            + "Content-Type: application/octet-stream\r\n"
+            + "Content-Transfer-Encoding: base64\r\n"
+            + "\r\n"
+            + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\r\n"
+            + "\r\n"
+            + "------Boundary101--\r\n"
+            + "\r\n"
+            + "------Boundary102--\r\n"
+            + "\r\n"
+            + "------Boundary103--\r\n";
+
+    private int mMimeBoundary;
+
+    public MessageTest() {
+        super();
+    }
+
+    public void testMessage() throws MessagingException, IOException {
+        MimeMessage message;
+        ByteArrayOutputStream out;
+
+        BinaryTempFileBody.setTempDirectory(getContext().getCacheDir());
+
+        mMimeBoundary = 101;
+        message = nestedMessage(nestedMessage(sampleMessage()));
+        out = new ByteArrayOutputStream();
+        message.writeTo(out);
+        assertEquals(EIGHT_BIT_RESULT, out.toString());
+
+        mMimeBoundary = 101;
+        message = nestedMessage(nestedMessage(sampleMessage()));
+        message.setUsing7bitTransport();
+        out = new ByteArrayOutputStream();
+        message.writeTo(out);
+        assertEquals(SEVEN_BIT_RESULT, out.toString());
+    }
+
+    private MimeMessage nestedMessage(MimeMessage subMessage)
+            throws MessagingException, IOException {
+        BinaryTempFileMessageBody tempMessageBody = new BinaryTempFileMessageBody();
+        tempMessageBody.setEncoding(MimeUtil.ENC_8BIT);
+
+        OutputStream out = tempMessageBody.getOutputStream();
+        try {
+            subMessage.writeTo(out);
+        } finally {
+            out.close();
+        }
+
+        MimeBodyPart bodyPart = new MimeBodyPart(tempMessageBody, "message/rfc822");
+        bodyPart.setHeader(MimeHeader.HEADER_CONTENT_DISPOSITION, "attachment");
+        bodyPart.setEncoding(MimeUtil.ENC_8BIT);
+
+        MimeMessage parentMessage = sampleMessage();
+        ((Multipart) parentMessage.getBody()).addBodyPart(bodyPart);
+
+        return parentMessage;
+    }
+
+    private MimeMessage sampleMessage() throws MessagingException, IOException {
+        MimeMessage message = new MimeMessage();
+        message.setFrom(new Address("from@example.com"));
+        message.setRecipient(RecipientType.TO, new Address("to@example.com"));
+        message.setSubject("Test Message");
+        message.setHeader("Date", "Wed, 28 Aug 2013 08:51:09 -0400");
+        message.setEncoding(MimeUtil.ENC_8BIT);
+
+        NonRandomMimeMultipartTest multipartBody = new NonRandomMimeMultipartTest();
+        multipartBody.setSubType("mixed");
+        multipartBody.addBodyPart(textBodyPart(MimeUtil.ENC_8BIT));
+        multipartBody.addBodyPart(textBodyPart(MimeUtil.ENC_QUOTED_PRINTABLE));
+        multipartBody.addBodyPart(binaryBodyPart());
+        message.setBody(multipartBody);
+
+        return message;
+    }
+
+    private MimeBodyPart binaryBodyPart() throws IOException,
+            MessagingException {
+        String encodedTestString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                + "abcdefghijklmnopqrstuvwxyz0123456789+/";
+
+        BinaryTempFileBody tempFileBody = new BinaryTempFileBody();
+
+        InputStream in = new Base64InputStream(new ByteArrayInputStream(
+                encodedTestString.getBytes("UTF-8")));
+
+        OutputStream out = tempFileBody.getOutputStream();
+        try {
+            IOUtils.copy(in, out);
+        } finally {
+            out.close();
+        }
+
+        MimeBodyPart bodyPart = new MimeBodyPart(tempFileBody,
+                "application/octet-stream");
+        bodyPart.setEncoding(MimeUtil.ENC_BASE64);
+
+        return bodyPart;
+    }
+
+    private MimeBodyPart textBodyPart(String encoding)
+            throws MessagingException {
+        TextBody textBody = new TextBody(
+                  "Testing.\r\n"
+                + "This is a text body with some greek characters.\r\n"
+                + "αβγδεζηθ\r\n"
+                + "End of test.\r\n");
+        textBody.setCharset("utf-8");
+        MimeBodyPart bodyPart = new MimeBodyPart(textBody, "text/plain");
+        MimeUtility.setCharset("utf-8", bodyPart);
+        bodyPart.setEncoding(encoding);
+        return bodyPart;
+    }
+
+    private class NonRandomMimeMultipartTest extends MimeMultipart {
+
+        public NonRandomMimeMultipartTest() throws MessagingException {
+            super();
+        }
+
+        @Override
+        public String generateBoundary() {
+            StringBuilder sb = new StringBuilder();
+            sb.append("----Boundary");
+            sb.append(Integer.toString(mMimeBoundary++));
+            return sb.toString();
+        }
+
+    }
+
+}