offlineimap does not delete messages on server

[ael]

> 
> This message is a re-edition of similar messages I've sent to Debian bug
> #626417:
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=626417
> 
> I am posting here because this problem is really annoying, and it is probably
> affecting other people.
> 
> I am using offlineimap version 6.3.3 (Debian revision 3, but that should make no
> difference).
> 
> Since I upgraded to the latest version of offlineimap my INBOXes started
> behaving weirdly, as if they were not being properly sync'ed with the IMAP
> servers. I move all my read messages to to local folders (not handled by
> offlineimap). But when sync again with offlineimap, those messages come back to
> my INBOX: it seems offlineimap did not delete them on the server, or did not
> perceived the fact that they were deleted locally.

I am seeing something a bit similar here. Also debian 6.3.3-3.
The odd thing is that I have upgraded offlineimap to 6.3.3-3 on two
386 boxes, but see the problem on only one box, and (so far) on only
1 email account (I have several).

In my case at least I get a trace back:

=================================================================

 ***** Processing account ntlspam
 Copying folder structure from Gmail to Maildir
 Establishing connection to imap.ntlworld.com:993.
ntlspamserv: Enter password: 
Folder sync [ntlspam]:
 Syncing Follow up: Gmail -> Maildir
 Syncing INBOX: Gmail -> Maildir
 Syncing Misc: Gmail -> Maildir
 Syncing Priority: Gmail -> Maildir
 Deleting 9 messages (28769, 28790, 28793, 28837, 28868, 28882, 28926, 28973, 28833) in Gmail[INBOX]
 Syncing Trash: Gmail -> Maildir
 WARNING: ERROR attempting to sync flags for account ntlspam:Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/offlineimap/folder/Base.py", line 486, in syncmessagesto
    action(dstfolder, statusfolder)
  File "/usr/lib/pymodules/python2.6/offlineimap/folder/Base.py", line 397, in syncmessagesto_delete
    folder.deletemessages(deletelist)
  File "/usr/lib/pymodules/python2.6/offlineimap/folder/IMAP.py", line 570, in deletemessages
    self.deletemessages_noconvert(uidlist)
  File "/usr/lib/pymodules/python2.6/offlineimap/folder/Gmail.py", line 56, in deletemessages_noconvert
    imapobj.select(self.getfullname())
  File "/usr/lib/pymodules/python2.6/offlineimap/imaplibutil.py", line 52, in select
    result = self.__class__.__bases__[1].select(self, mailbox, readonly)
  File "/usr/lib/pymodules/python2.6/offlineimap/imaplib2.py", line 944, in select
    self._deliver_exc(self.readonly, '%s is not writable' % mailbox, kw)
  File "/usr/lib/pymodules/python2.6/offlineimap/imaplib2.py", line 1314, in _deliver_exc
    raise exc(dat)
readonly: INBOX is not writable

 Syncing [Gmail]/Bin: Gmail -> Maildir
 Syncing [Gmail]/Drafts: Gmail -> Maildir
 Syncing [Gmail]/Sent Mail: Gmail -> Maildir
 Syncing [Gmail]/Spam: Gmail -> Maildir
 Syncing [Gmail]/Starred: Gmail -> Maildir
Account sync ntlspam:
 ***** Finished processing account ntlspam
===============================================================================

This was after using mutt to delete a few messages from my INBOX.
Of course, the INBOX permissions were correct.

If I run with offlineimap -1 to disable multithreading, all is well
which matches my feeling that it may be a synchronisation problem.
It might be relevant to note that the problem machine is rather old
and slow. So it may be exploring an unusual code path.

ael