Listening for SMTP (MS Exchange) on redundant routers

[w4nn4b1337]

I have no idea wher to pose this question so I will place this in a few areas so forgive me for multiple posts.
What we are doing is using Active-Active failover on two Cisco ASA's. The goal is to load balance across two Internet providers including all incoming and outgoing Internet, and Email traffic. What I haven't figured out is if one path fails and the second takes over, how do I have my SMTP traffic (in/out) switch over to the alternate route?
My first thougth is this will be a DNS issue but I'm not sure how that would work. Do I register my MX records for both ISPs for the same mail server? Any help is greatly appreciated.

Network+ / Security+ / C|EH /CCNA
Working towards CCNP and CWNA.

 

[elgrandeperro]

The smtp/mta protocol already handles this; it tries both MX records if they are weighted the same. So as long as both can route mail, advertise both at the same MX precedence. If one goes down, then the other will be tried. If you prefer one over the other, make the preferred one at a lower number. It will try the preferred,then the second if the first is down.

 

[w4nn4b1337]

That is great news. That gives me a direction to look. Thanks

Network+ / Security+ / C|EH /CCNA
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