diff --git a/src/com/fsck/k9/mail/Body.java b/src/com/fsck/k9/mail/Body.java
index 7b18a75a7..93960892c 100644
--- a/src/com/fsck/k9/mail/Body.java
+++ b/src/com/fsck/k9/mail/Body.java
@@ -8,7 +8,21 @@ import java.io.OutputStream;
 import com.fsck.k9.mail.store.UnavailableStorageException;
 
 public interface Body {
+    /**
+     * Returns the raw data of the body, without transfer encoding etc applied.
+     * TODO perhaps it would be better to have an intermediate "simple part" class where this method could reside
+     *    because it makes no sense for multiparts
+     */
     public InputStream getInputStream() throws MessagingException;
+
+    /**
+     * Sets the content transfer encoding (7bit, 8bit, quoted-printable or base64).
+     */
     public void setEncoding(String encoding) throws UnavailableStorageException, MessagingException;
+
+    /**
+     * Writes the body's data to the given {@link OutputStream}.
+     * The written data is transfer encoded (e.g. transformed to Base64 when needed).
+     */
     public void writeTo(OutputStream out) throws IOException, MessagingException;
 }
diff --git a/src/com/fsck/k9/mail/BodyPart.java b/src/com/fsck/k9/mail/BodyPart.java
index 163fe7ba6..1118304ba 100644
--- a/src/com/fsck/k9/mail/BodyPart.java
+++ b/src/com/fsck/k9/mail/BodyPart.java
@@ -14,5 +14,6 @@ public abstract class BodyPart implements Part {
 
     public abstract void setEncoding(String encoding) throws MessagingException;
 
+    @Override
     public abstract void setUsing7bitTransport() throws MessagingException;
 }
diff --git a/src/com/fsck/k9/mail/MessagingException.java b/src/com/fsck/k9/mail/MessagingException.java
index b5f563a1b..d33014603 100644
--- a/src/com/fsck/k9/mail/MessagingException.java
+++ b/src/com/fsck/k9/mail/MessagingException.java
@@ -28,9 +28,9 @@ public class MessagingException extends Exception {
         return permanentFailure;
     }
 
+    //TODO setters in Exception are bad style, remove (it's nearly unused anyway)
     public void setPermanentFailure(boolean permanentFailure) {
         this.permanentFailure = permanentFailure;
     }
 
-
 }
diff --git a/src/com/fsck/k9/mail/transport/SmtpTransport.java b/src/com/fsck/k9/mail/transport/SmtpTransport.java
index 0b2ef25d8..8c6d178b4 100644
--- a/src/com/fsck/k9/mail/transport/SmtpTransport.java
+++ b/src/com/fsck/k9/mail/transport/SmtpTransport.java
@@ -511,6 +511,7 @@ public class SmtpTransport extends Transport {
         if (mLargestAcceptableMessage > 0 && ((LocalMessage)message).hasAttachments()) {
             if (message.calculateSize() > mLargestAcceptableMessage) {
                 MessagingException me = new MessagingException("Message too large for server");
+                //TODO this looks rather suspicious... shouldn't it be true?
                 me.setPermanentFailure(possibleSend);
                 throw me;
             }
@@ -545,14 +546,13 @@ public class SmtpTransport extends Transport {
                 possibleSend = false;
             }
 
+            //TODO this looks rather suspicious... why is possibleSend used, and why are 5xx NOT permanent (in contrast to the log text)
             me.setPermanentFailure(possibleSend);
             throw me;
         } finally {
             close();
         }
 
-
-
     }
 
     @Override