[Dovecot] Dovecot readable compressed mail archive

[Timo Sirainen]

On 4.12.2013, at 20.52, Dave Hall <davehall at cs.binghamton.edu> wrote:

> Is Dovecot able to create and/or read any sort of compressed mail archive?  We have a large installation with a few users who need to keep a large amount of email available.  With maildir this means a large number of individual files, leading to additional load on our backup process.  Even using a compressed mbox file as an archive would help, but only if Dovecot is able to interact with this file seamlessly while keeping current email in the maildir format.

You could move the old mails to a compressed mbox file, but it would need to be in a separate namespace, e.g. INBOX maildir and Archive/INBOX mbox. Also the archive updating doesn’t have any existing scripts.

On top of that you could also use virtual plugin to merge the old and new mails into the same folder (e.g. NewMails/INBOX maildir, Archive/INBOX mbox, while INBOX = virtual). http://wiki2.dovecot.org/Plugins/Virtual The main problem would be archive updating though. Virtual plugin would suddenly see a lot of old mails getting expunged, while a lot of new mails arrive at the other folder. So basically it means that the user’s client will have to redownload all the moved mails. Depending on the client it could also sort them as new mails (if sorting by UID instead of sent/received date).