[Dovecot] dovecot-uidlist cleanup

[Thomas Zajic]

>From http://www.dovecot.org/list/dovecot/2008-June/031235.html:

> > I have noticed that the entries in the dovecot-uidlist files don't seem
> > to get updated when an email is deleted or moved to .Trash. It appears
> > that this list list would just keep growing over time, being full of no
> > longer used filenames, and must tend to increase its processing
> > overhead.
> 
> The deleted entries are removed when a new message arrives to the
> mailbox. So it's just an optimization not to waste disk I/O on rewriting
> the file when it's not necessary. If this isn't happening, there's
> something wrong or you're misunderstanding something.


>From http://www.dovecot.org/list/dovecot/2008-June/031403.html:

> > However, I DO clobber the dovecot-uidlist in .Trash as part of my 
> > monthly housekeeping because it tends to get very large
> 
> All the expunged messages get removed from it the next time a new
> message is added to the mailbox. So there should be no need to delete
> it. (v1.1 doesn't always recreate the file, but it gets rewritten if the
> resulting file would be 70% of the current size or less.)


If I understand this correctly, dovecot is supposed to clean out all
deleted/expunged messages from dovecot-uidlist whenever a new message
is added to the respective mailbox - right? This doesn't actually seem
to be the case at least with dovecot-1.0:

[root at airframe]:~# dovecot --version
1.0.14
[root at airframe]:~# 
[root at airframe]:~# du -h ~user/Maildir/.Trash/dovecot-uidlist 
13M	/home/user/Maildir/.Trash/dovecot-uidlist
[root at airframe]:~# wc -l < ~user/Maildir/.Trash/dovecot-uidlist
289769
[root at airframe]:~# ls -1 ~user/Maildir/.Trash/cur/ | wc -l
14
[root at airframe]:~# 
[root at airframe]:~# du -h ~user/Maildir/.Logs.System\ Checks/dovecot-uidlist 
3,5M	/home/user/Maildir/.Logs.System Checks/dovecot-uidlist
[root at airframe]:~# wc -l < ~user/Maildir/.Logs.System\ Checks/dovecot-uidlist
85188
[root at airframe]:~# ls -1 ~user/Maildir/.Logs.System\ Checks/cur/ | wc -l
16069

The only mailbox where this seems to work properly is INBOX:

[root at airframe]:~# du -h ~user/Maildir/.INBOX/dovecot-uidlist 
4,0K	/home/user/Maildir/.INBOX/dovecot-uidlist
[root at airframe]:~# wc -l < ~user/Maildir/.INBOX/dovecot-uidlist
18
[root at airframe]:~# ls -1 ~user/Maildir/.INBOX/cur/ | wc -l
17
[root at airframe]:~# 

The server runs sendmail, the LDA is procmail, not dovecot's deliver. The
.procmailrc is empty except for the bare minimum, though, all other sorting
is done either via Thunderbird message filters or manually:

[root at airframe]:~# cat ~user/.procmailrc 
MAILDIR=$HOME/Maildir
DEFAULT=.INBOX/
[root at airframe]:~# 

Any hints?


Thanks,
Thomas