Incomplete message fetching (IMAP, Bug?)

User Help for Mozilla Thunderbird
Posts: 3
Joined: May 2nd, 2020, 3:20 am

Post Posted May 24th, 2020, 7:02 am


I am running a self-written email server based on Greenmail Java.
There is an issue with attachments and the general message size.

A normal text-only message is requested from TB with:
Code: Select all
ID fetch 33 (UID RFC822.SIZE BODY[])

This works completely fine unless the message exceeds 65kb, which is the chunk size (
Then TB is only able to fetch the first chunk. After this, it issues the "logout" command and closes the connection, which ultimately leaves the message corrupted.

This is the typical single chunk command with a partial:
Code: Select all
UID fetch 34 (UID RFC822.SIZE BODY[]<0.65536>)

Which is followed by the logout.

This only happens if TB is set to not download messages from the server (Account Settings -> Don't download messages ... (set to 50kB)). If it is allowed to download messages, it will just download everything on startup (by correctly requesting all chunks).

Thunderbird is able to request multiple chunks of a "larger" message only if it does download the message at startup. If, however, it cannot download the message on startup (because it is disabled), it is not able to display a "multi chunk" mail (it only requests the first chunk and then closes the connection).

This seems like a bug to me, maybe somebody encountered this before?



User avatar
Posts: 46826
Joined: July 30th, 2003, 5:06 pm

Post Posted May 25th, 2020, 10:05 am

I haven't run into this because I normally don't get messages with that large a message body, and don't set a download limit. I vaguely do remember there being several bugs with chunks in the last couple of years where the temporary workaround was to disable chunks.

I suggest you file a bug report, attaching a IMAP log file. It would help if you duplicate the problem not just for your server, but a public one such as gmail or outlook. That way you avoid any potential finger pointing saying its due to your code.

If you file a bug report please post a link to it.

Return to Thunderbird Support

Who is online

Users browsing this forum: No registered users and 11 guests