[Dovecot] IMAP message ID bad for very old message

[Timo Sirainen]

On Mon, 2011-05-16 at 15:41 +0100, a.smith at ukgrid.net wrote:
> Quoting Timo Sirainen <tss at iki.fi>:
> > Have you checked if there are any errors in Dovecot logs? There are some
> > reasons why Dovecot might give a new UID to an existing mail. dovecot -n
> > output might also be useful.
> >
>    thanks for the reply. I just checked and the file names are correct  
> for the mails to be ordered chronologically, so nothing weird going on  
> there that would cause a prob.
> I can't see any errors relating to this in the logs, but my logs a  
> several thousand lines per day so is there any particular error  
> message I should be looking for? A grep -i err doesn't show anything  
> interesting...

Try grepping for "Warning" also. I usually put error logs to a different
file. That file should stay empty (except for Dovecot stop messages).

> mail_location = maildir:/var/spool/mail/%d/%u
> mail_nfs_index = yes
> mail_nfs_storage = yes

Are you using NFS? With just one server or more? What NFS server?