broken sync: IMAP -> local -> IMAP

[Timo Nentwig]

On Thu, 1 Dec 2011, Sebastian Spaeth wrote:

> Date: Thu, 01 Dec 2011 10:47:22 +0100
> From: Sebastian Spaeth <Sebastian at SSpaeth.de>
> To: Timo Nentwig <foo at nentwig.biz>,
>     offlineimap-project at lists.alioth.debian.org
> Subject: Re: broken sync: IMAP -> local -> IMAP
> 
> On Tue, 22 Nov 2011 13:10:04 +0100 (CET), Timo Nentwig <foo at nentwig.biz> wrote:
>> Hi!
>>
>> I do sync between 2 IMAP servers. Actually, it's a one-way backup sync from
>> remote to local. I run into validility errors all the time with by INBOX.Sent
>> folder. Tried all kinds of file deletions (last attempt: find .offlineimap/ |
>> grep Sent) and resyncs and stuff and know have the behaviour that all mail is
>> downloaded from remote to local and then sent
>> back to remote (and then probably sync'ed back again, i.e. duplicating all
>> mails).
>
> Hi,
>
> Folder validity errors occur when the UIDvalidity value changes. So
> servers change the UIDvalidity whenever a folder was empty. Does your
> syncing involve completely emptying the folders?
>
> Sebastian

Sure, I deleted all local mail via IMAP (i.e. not on disk). 6.4.0, BTW.