[Dovecot] IMAP message ID bad for very old message

[Timo Sirainen]

On Mon, 2011-05-16 at 16:31 +0100, a.smith at ukgrid.net wrote:
> Quoting Timo Sirainen <tss at iki.fi>:
> 
> >
> > Try grepping for "Warning" also. I usually put error logs to a different
> > file. That file should stay empty (except for Dovecot stop messages).
> 
> Hi, I don't have a dovecot log specified in the config, so I believe  
> everything goes to syslog which I think all ends up in either maillog  
> or messages. I don't see anything in there with "Warning".

Well, difficult to say then. It kind of sounds like Dovecot suddenly
doesn't see that some old message is still there (not returned by
readdir()) but then later it sees that it's there again, and gives it a
new UID. Although in many such cases Dovecot should notice this itself
and log a warning/error about it.

You could try saving a backup of dovecot-uidlist periodically and when
this happens again, see what exactly changed in the file.