Sebastian Berm - Sebsoft wrote:
> What I want to accomplish is this:
> * Create a backup/fallback mailserver to receive mail while other servers
> are offline. This would mean it needs to catch all mail to *@domain.ext
> found in /var/exim/named_domainlist (which has a domain list that
> dynamically updates at every DNS change) and try to send it to the normal
> mail server for a week or so before dropping it, it would help if it also
> passed through the normal spam check
> * Use the same mailserver to be standard mailserver for a few unimportant
> domains/hosting accounts that make up for the colocation cost of this
> particulair server, these don't need a backup.
>
> Is this doable in any way ?
> I'm rather feeling like my head is hitting a brick wall here ;)
Yes but....
As soon as your secondary appears in the DNS, the spammers will
rush to it. They prefer 2MX's since they often aren't as picky
about usernames actually matching real users, and about running
any real antispam checks. After all, it's "too hard" to keep
the configurations in-sync, right?
Wrong.
The only way to survive, say I, is to ensure that your primary
and secondary(s) are working from the same information.
(Actually, my 2MX is *more* nasty than my primary; the delays
are bigger when someone annoys me). So my user and domain
config lives in a database on a seperate machine, and both
my MX's access it. For extra resilience I'd replicate that
database server, and split machines geographically - but I'm
not that well organised yet.
Cheers,
Jeremy
