What's the best possible email failover solution

[Jason Taylor]

Bill Moran wrote:
> Hey,
> 
> I know questions like this get asked a lot, but I'm going to be really specific.
> 
> I know how to set up failover with a backup MX.  That's not what I'm looking
> for.  We have a cyrus-imap server with lots of users connecting via IMAP,
> while everything gets backed up, this only happens once a night.  Thus, if the
> server were to go up in smoke right before the backup occurred, we'd lose
> something like 23 hours worth of emails.
> 
> Does anyone have a solution to provide real-time mirroring of IMAP folders?
> I don't mind manual intervention to get the thing running again, I just want
> to ensure that if an email is received, it's on both machines and can't get
> lost.  Is there a way to get real-time replication of cyrus (I'm no cyrus
> guru, another fellow set this up)
> 
> I'm not tied to Cyrus either, if there's another solution, I'd be happy to
> implement it.
> 
> I have an idea ... by using Dovecot with PostgreSQL storing the actual mail
> folders, with Slony installed to provide real-time replication of the Postgres
> database ... I don't know if Dovecot is able to store the actual mail folders
> in Postgres yet, though ... Anyone?
> 

I was able to dig up a few leads:

http://www-uxsup.csx.cam.ac.uk/~dpc22/cyrus/replication.html
http://216.239.57.104/search?q=cache:Xu7aew9dgpsJ:asg.web.cmu.edu/archive/message.php%3Fmailbox%3Darchive.cyrus-devel%26msg%3D594+cyrus+replication&hl=en
http://www.irbs.net/internet/info-cyrus/0405/0279.html
http://www.drbd.org/