irreversible silent loss of mail when server account is full

[Adam Spiers]

Hi all,

Regret to announce that I just lost the last 14 days of email due to a
bug in offlineimap :-(  It took a while but I finally tracked down the
bug:

When savemessage() performed the APPEND command to upload a new local
mail to the Groupwise IMAP server I use, the server responded:

    NO APPEND The 1500 MB storage limit has been exceeded.

This is correct behaviour according to RFC 3501:

    http://tools.ietf.org/html/rfc3501#section-6.3.11

but savemessage() considered this as a successful upload, returned UID
zero, and offlineimap then irreversibly deleted the local copy :-/
Here is the fix:

    https://github.com/OfflineIMAP/offlineimap/pull/29

However, this led me to notice a separate issue where single-threaded
mode doesn't properly handle exceptions.  I'll send a separate mail
about that.

Regards,
Adam