[CentOS] Converting to maildir

Tue Jan 4 14:12:31 UTC 2011
Adam Tauno Williams <awilliam at whitemice.org>

On Tue, 2011-01-04 at 09:05 -0500, Jason Pyeron wrote:
> > On Mon, 2011-01-03 at 20:17 -0500, Jason Pyeron wrote:
> > > Looking for a guide on converting to Maildir.
> > > Here are our relevant specs.
> > > sendmail-8.12.11-4.RHEL3.6 (we may not be able to upgrade 
> > this due to 
> > > too many
> > > modifications)
> > > imap-2002d-14
> > > procmail-3.22-10.el3.centos.0
> > > To a maildir setup...
> > > <rant>
> > > I was in a panic today at work because the backup server is 
> > filling up 
> > > too quickly, backing up peoples email. Further it is not backing up 
> > > often enough. I just lost all of today's email. I hate mbox 
> > and imap and outlook...
> > > </rant>
> > > All the maildir stuff I can find is postfix oriented.
> > Because sendmail is rapidly fading into history
> There are too many modifications to abandon it right now. Besides it is stable
> as a rock.
> > >  From what I can read in
> > > procmail man pages, it supports maildir and sendmail uses 
> > procmail as 
> > > the LDA, hence sendmail "supports" it.
> > There are numerous IMAP servers that support maildir, and 
> > scripts to import MBOX files - that is how I would approach 
> > it.  [But then I wouldn't use Maildir; I mean, really, who 
> > cares what format your messages are in - use IMAP and network 
> The backup server. As one file per mailbox, the backup server is backing up over
> 25G/hour. These files are not subject to de-duplication. With one message per
> file only the new messages would get added to the backup size. 
> What would you use besides Maildir?

I use Cyrus IMAPd - where external modification of the mailstore is
forbidden [or at least very frowned upon].  That way it uses its own
internal storage format that can be customized to be efficient.  It also
means it can keep *consistent* meta-data databases, such as search
indexes, which are *IMPOSSIBLE* if other clients are diddling around in
the mailstore.   These databases add features, performance, and
stability.  You also get things like delayed expunge and duplicate
supression [which can save scads of disk space].  All access to the
mailstore is via IMAP or POP.  Messages are placed in the mailstore by
the MTA (sendmail / postfix) via LMTP - so Cyrus can also run the SIEVE
filtering language to provide on-delivery message filtering.


Administrative tools are provided to manipulate the message store in a
consistent and reliable way.

> > access your message store.  Cyrus IMAPd will index and filter 
> > all your messages for you].