Large email causes OfflineIMAP sync failure

Question

I am able to download emails from the server with OfflineIMAP. I then switched email providers, so OfflineIMAP copied my emails to the new server. One message has a large attachment, 33 MB, and I now get this error every time I try syncing:

Folder Deleted Items [acc: EmailAccount]:
 Copy message UID -660 (1/660) LocalEmailAccount:Deleted Items -> RepositoryEmailAccount:Deleted Items
Account sync EmailAccount:
 *** Finished account 'EmailAccount' in 0:21
Thread 'Folder Deleted Items [acc: EmailAccount]' terminated with exception:
Traceback (most recent call last):
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/threadutil.py", line 160, in run
    Thread.run(self)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/accounts.py", line 668, in syncfolder
    localfolder.syncmessagesto(remotefolder, statusfolder)
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/folder/Base.py", line 1116, in syncmessagesto
    action(dstfolder, statusfolder)
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/folder/Base.py", line 944, in __syncmessagesto_copy
    self.copymessageto(uid, dstfolder, statusfolder, register=0)
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/folder/Base.py", line 844, in copymessageto
    new_uid = dstfolder.savemessage(uid, message, flags, rtime)
  File "/usr/local/Cellar/offlineimap/7.3.3/libexec/offlineimap/folder/IMAP.py", line 675, in savemessage
    raise OfflineImapError(msg, OfflineImapError.ERROR.REPO)
OfflineImapError: Saving msg () in folder 'Deleted Items', repository 'RepositoryEmailAccount' failed (abort). Server responded: NO ['[LIMIT] Maximum message size reached (0.279 + 15.644 + 15.966 secs).']

and then the dump of the message and the attachment.

Short of deleting the email or severing the attachment from the email, is this possible to fix?

Answer 1

From the last error, it looks like the email you are trying to copy exceeds the max message size for the server.

This is a setting the email provider will have. If you exceed it, they will refuse the message. You will most likely need to remove the attachment (if you can) from the original message.

Also keep in mind that attachments almost triple in size when sent via email. The encoding process -- converting a binary file into an ascii one -- usually expands the size tremendously. It might not be that 33MB is too big in and of itself, but once it's encoded and swells to 90MB, that might be where the problem is.