diff --git a/src/com/fsck/k9/activity/MessageCompose.java b/src/com/fsck/k9/activity/MessageCompose.java
index 5952c8ccc..75805e9b6 100644
--- a/src/com/fsck/k9/activity/MessageCompose.java
+++ b/src/com/fsck/k9/activity/MessageCompose.java
@@ -36,6 +36,7 @@ import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.StringTokenizer;
+import org.apache.james.mime4j.codec.EncoderUtil;
 
 public class MessageCompose extends K9Activity implements OnClickListener, OnFocusChangeListener
 {
@@ -747,10 +748,41 @@ public class MessageCompose extends K9Activity implements OnClickListener, OnFoc
             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()));
-                bp.addHeader(MimeHeader.HEADER_CONTENT_TYPE, String.format("%s;\n name=\"%s\"", attachment.contentType, attachment.name));
+
+                MimeBodyPart bp = new MimeBodyPart(
+                        new LocalStore.LocalAttachmentBody(attachment.uri, getApplication()));
+
+                /*
+                 * Correctly encode the filename here. Otherwise the whole
+                 * header value (all parameters at once) will be encoded by
+                 * MimeHeader.writeTo().
+                 */
+                bp.addHeader(MimeHeader.HEADER_CONTENT_TYPE, String.format("%s;\n name=\"%s\"",
+                        attachment.contentType,
+                        EncoderUtil.encodeIfNecessary(attachment.name,
+                                EncoderUtil.Usage.WORD_ENTITY, 7)));
+
                 bp.addHeader(MimeHeader.HEADER_CONTENT_TRANSFER_ENCODING, "base64");
-                bp.addHeader(MimeHeader.HEADER_CONTENT_DISPOSITION, String.format("attachment;\n filename=\"%s\";\n size=%d", attachment.name, attachment.size));
+
+                /*
+                 * TODO: Oh the joys of MIME...
+                 * 
+                 * From RFC 2183 (The Content-Disposition Header Field):
+                 * "Parameter values longer than 78 characters, or which
+                 *  contain non-ASCII characters, MUST be encoded as specified
+                 *  in [RFC 2184]."
+                 *  
+                 * Example:
+                 * 
+                 * Content-Type: application/x-stuff
+                 *  title*1*=us-ascii'en'This%20is%20even%20more%20
+                 *  title*2*=%2A%2A%2Afun%2A%2A%2A%20
+                 *  title*3="isn't it!"
+                 */
+                bp.addHeader(MimeHeader.HEADER_CONTENT_DISPOSITION, String.format(
+                        "attachment;\n filename=\"%s\";\n size=%d",
+                        attachment.name, attachment.size));
+
                 mp.addBodyPart(bp);
             }