Re: unexpecteg tag, and uidvalidity changes

[Oswald B. <osw...@gm...>]

On Sat, Nov 07, 2015 at 12:33:23PM +0100, Peter P. wrote:
> Now when re-syncing, the process stops after a few synced mails with the
> message:
> 
> 	IMAP error: unexpected tag XYZ
> 
> where XYZ is any random gibberish, sometimes parts out of email headers
> and bodies. Upon re-running the same sync, the contents of XYZ change.
> 
> This is currently on a Microsoft Exchange IMAP4 server, and has also
> happened on a Groupwise server in the last days, with isync isync 1.1.2
> 
i'm occasionally getting that from exchange as well. re-running the sync
is a sufficiently functional workaround.

if you can reproduce this with sufficient reliability, it would be
interesting to see the logs from
   strace -s100000 -r -o mbsync.strace mbsync -VV [...] >& mbsync.out
some notes:
- no ssl. use
     Tunnel "openssl s_client -connect host:port -quiet -no_ign_eof"
  if you need to.
  - if this actually avoids the issue, we know where to look.
- if you redact the log, make sure not to change the length of any
  string. but it's better if you can reproduce it with a mailbox you
  can show me. also, using an authentication mechanism which does not
  disclose usable information (basically, anything except LOGIN and
  PLAIN is ok) would remove the need to redact anything.

also, you should use the 1.2 branch of mbsync. use -DN instead of -VV
then.

> What could be common reasons for the servers to change their
> uidvalidity?
>
just for the heck of it, as far as i'm concerned.
i suspect some kind of server maintenance is triggering it.

> Why is this an issue to me with mbsync, but not with something like
> thunderbird, or mutt-accessing-imapServer-directly?
> Is there any better, yet still safe and simple, way to work around
> changed uidvalidities, or even more permanent fixes?
> 
nope.
the topic has been discussed to death on this list already.