dovecot-uidlist is not up-to-date

[Dmitry Filonov]

Hi,

  Am using dovecot-2.2.10-8 on Centos-7 and everything seemed to be 
totally fine for many years. Now am trying to migrate our on-premises 
mail server to the cloud and I had to get some statistics. I was doing 
that using the doveadm utility.

Unfortunately I found that the numbers don't match if I check the real 
messages in my Maildirs. For some account doveadm was reporting number 
of messages but that account didn't have any messages stored at all.

So I looked a bit further and found that doveadm utility reports data 
form indexes and indexes are built using dovecot-uidlist data. For quite 
some folders these files have way more data than actual mailbox has. For 
example, my personal Inbox has 569 messages but dovecot-uidlist has 716 
entries.

I don't know when and how that happened but this happens a lot on many 
different mailboxes on my server. I never touched dovecot-uidlist files 
outside of dovecot. I might have removed messages from Maildirs though, 
but not at this scale.

Now the question is if there's any way to tell dovecot to rebuild 
dovecot-uidlist files using actual Maildir data. I don't want to remove 
dovecot-uidlist files as this triggers the whole mailbox being 
re-downloaded by the imap client. With some accounts having over 100Gb 
of mail this is too much of a hassle. I just need dovecot itself to fix 
it's data.

Thanks,

Fil

-- 
Dmitry Filonov
Network Analyst
300 Longwood Ave.
Enders-1262.2
Boston, MA 02115
617-919-4702