[afnog] Two mail servers in the same domain

[Stephane Bortzmeyer]

On Fri, Dec 12, 2008 at 06:31:33PM +0000,
 Kone <enokb at yahoo.fr> wrote 
 a message of 40 lines which said:

> I have a mail server running under postfix and dns server in my
> network. I want to install an other mail server to backup mails.

In most cases, it is a bad idea. Since you have an email address in
".fr", I assume you read french, so you can see details:

http://www.bortzmeyer.org/mx-secondaire.html

> I plan to make a backup using rsync with cron.

I smell trouble. Do you really want to synchronize the mailboxes on
the two servers? rsync is purely master/slave so it will have trouble
to do so.