offlineimap smart backup synchronization = bidirectional synchronization without deleting any messages

proxym wproxym at
Tue Dec 18 14:27:15 GMT 2012

OK. Thanks.

I removed this from patch:
+        import sys
+        sys.exit()

And I placed
no-delete-local = yes
to [Account main] section.

After this patched offlineimap starts working correctly and writes:
for every folder.

But synchronisation is broken now. Deleted from remote imap messages
are not deleted from local maildir, but these messages are not
restoried to remote imap. It is very bad.
How to add auto restoring messages to remote imap repository?

2012/12/4 Edward Z. Yang <ezyang at>:
> You might be interested the modified OfflineIMAP algorithm
> described here:
> (see the bottom of the post).  A PoC patch is here:
> Edward
> Excerpts from proxym's message of Mon Dec 03 16:02:12 -0800 2012:
>> No no no...
>> I don't want to use snapshots/tarbals. I just want bidirectional
>> append only mode switch in OfflineIMAP and it's config file. Also I
>> need allowing for editing of Drafts as exception in bidirectional
>> append mode.
>> I already fixed this problem partially. But fix is ugly: I just call cp -al
>> command to create hard links of all my letters (messages) after
>> offlineimap finish synchronization. As you know every file already has
>> counter of hard links to him with value 1. It is in
>> ext2/ext3/ext4/ntfs file systems.
>> cp -al just create something which I can name as new "file header" and
>> increase hard link counter of file. If counter is 0, then no hard
>> links exists anymore (file is totally removed from file system and
>> will be rewrited by something else later). So hard links is good
>> temporary solution for me.
>> Hard links additional "headers" takes 44M for 1,4G Mail folder in my
>> ext3 file system now.
>> I don't want tarbals. I choosed Maildir format specially, because it
>> keeps one message by file (actually in raw email format, which is
>> better). Even in case of file system damage I can restore most of my
>> messages because of Maildir.
>> I know some people, which lost half or even all mail messages, because
>> Google just cleaned their Gmail mailboxes by unknown reason (support
>> answered that messages are not restorable). Offlineimap will remove
>> local copy of messages in this case while next synchronuzation without
>> any warning. Removing of messages by Google is in TERMS AND CONDITIONS
>> of Gmail, if you did not know. Same is for any other free Mail server
>> (maybe for non-free too).
>> Maybe I don't know something about 'readonly' option... I thought it
>> makes Maildir Mailbox not writable at all and it is not possible to
>> add new email massages when readonly option is activated... Maybe I am
>> not right... ?
>> Thank you.
>> 2012/12/3 Nicolas Sebrecht <nicolas.s-dev at>:
>> > On Sat, Dec 01, 2012 at 05:15:32PM +0300, proxym wrote:
>> >> Offlineimap does bidirectional synchronization, but it is not smart,
>> >> it's has not any options to configure behavior for deleting messages.
>> >>
>> >> I just want to do bidirectional synchronization without deleting
>> >> anything ALWAYS. How can I get it with offlineimap?
>> >
>> > You need more than OfflineIMAP for what you expect. Coupling OfflineIMAP
>> > with tarballs/snapshots of the local maildir could do the trick in your
>> > case.
>> >
>> > OfflineIMAP alone can be used as a backup tool ('readonly' option helps
>> > for the purpose) at the condition that the state of the mailbox is
>> > _known_ to be correct (so, the sync IS the backup). OfflineIMAP does not
>> > intend to provide history of backups or anything more advanced.
>> >
>> > --
>> > Nicolas Sebrecht

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