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I have a site that send out emails from a postfix server. They have multiple broadband lines for load balancing and failover. I want them to be able to send out emails though both lines without the risk of being blocked as spam.

Both lines have a static address and have a PTR record on them which also have a records that resolve to the IP addresses

in the myhostname =

SPF records are also being configured as well

my main question is: should the first line on go down would there be a risk of the emails being blocked as spam if they go though as myhostname is different?

Thank you

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Personally, I would arrange for both IP addresses to resolve to Then you don't have to worry about it. – Celada Feb 1 '13 at 16:24
up vote 1 down vote accepted

No, would not


  • (used in EHLO myhostname) always resolve to some IP
  • Paranoid-IP-check for server2's IP can be performed (server-IP-> hostname + hostname -> hostname-IP and server-IP == hostname-IP)

you have correctly configured SMTP-server from DNS-part

Read SMTP-lelated RFCs - it's useful reading for postmaster

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Thanks for your reply. It is good to know I am configuring the DNS side of our mail servers correctly – dgibbs Feb 12 '13 at 14:45

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