[Dovecot] Mails repopping

[Timo Sirainen]

On Fri, 2011-09-09 at 13:07 -0400, Simon Brereton wrote:

> I have a server that's been running Courier for about 6 years and in
> all that time I think I've only ever had 1 issues where an entire mail
> box was repopped by a webmail client.  However, since moving to a new
> server and dovecot 4 weeks ago, I've now had the webmail client repop
> this account 4 times (there are about 230 mails in the account).  
> 
> Is there a setting I need to tighten to prevent/remedy this?  I have
> no idea if it's happening on other accounts, but this is one that I
> see.  The format is maildir.  There has been no changes to the webmail
> client.

dovecot -n output would have been nice. Also do you see anything in
error logs?

If you're using the default pop3_uidl_format it'll rely on IMAP UIDs to
stay the same, and I guess it's possible that due to some other problem
they change (that should be logged as an error/warning though).

You could try setting pop3_uidl_format=%f, but it will cause everyone to
redownload mails. With newer Dovecot versions you could set
pop3_save_uidl=yes and when you think everyone's downloaded mails once
you can safely change the pop3_uidl_format.