multiple mail servers for one domain

William Attwood wattwood at gmail.com
Thu May 14 15:33:09 MDT 2009


There is a priority in DNS for each MX record.
MX mail.domain.com 10
MX mail2.domain.com 20
MX mail3.domain.com 30
MX mail4.domain.com 40


What will happen is the lower the number, the higher the priority; if mail.
isn't responding, it will try mail2, if that doesn't respond, it'll try
mail3 - if in the end none respond, it will wait a certain amount of time
and try again; eventually, if none work, it will bounce it back to you
undeliverable.

To get around the possibility of random e-mail delivery, I actually went
this route:

This is from my bind zone file:
IN MX 1 aspmx.l.google.com.
IN MX 5 alt1.aspmx.l.google.com.
IN MX 5 alt2.aspmx.l.google.com.
automail.domain.com. IN MX 1 automail.domain.com.
automail.commissionriver.com. IN A XXX.XXX.XXX.XXX



Than I have google setup to forward all unknown accounts to
automail.domain.com - which delivers cronjob e-mails so I didn't have to pay
for those.

If you don't want to send all unknowns from google to your 2nd mail server,
you can setup a Group and have it send to name at automail.domain.com

Does that make sense?




On Thu, May 14, 2009 at 3:25 PM, Daniel C. <dcrookston at gmail.com> wrote:

> On Thu, May 14, 2009 at 2:01 PM, William Atteood <wattwood at gmail.com>
> wrote:
> > Yes.  Setup a second mx say mail2.domain.com
>
> Won't this result in mail2.domain.com randomly getting emails for
> accounts that should go to mail1.domain.com?  It's my understanding
> that, while mail is *supposed* to be delivered to the MX records in
> order, it doesn't always happen that way, and that it's acceptable to
> deliver mail to any MX record for the domain.
>
> Practical upshot being, is it possible to make a non-MX DNS record and
> tell gmail to forward them to it?  If it is, this would prevent other
> mail systems from accidentally sending mail to the secondary server on
> accident.  But Gmail may only be happy with forwarding mail to MX
> records.
>
> -Dan
>
> /*
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-- 
Warm regards,
William Attwood
Idea Extraordinaire
wattwood at gmail.com
Vince Lombardi<http://www.brainyquote.com/quotes/authors/v/vince_lombardi.html>
- "We didn't lose the game; we just ran out of time."



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