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I was wondering whether we can point to same IP address for multiple A mail records.

Two days ago, I bought a domain (test1.com) and a dedicated server to host SmarterMail, let's say the server's IP address is 172.12.12.5. I have pointed an A record for mail to the IP address. So, if I ping to mail.test1.com, it will pointing to 172.12.12.5.

This morning, I bought again another domain (test2.com). I want to point A record for mail to same IP address. So, when I ping to mail.test2.com, it will pointing to 172.12.12.5.

Is it possible?

Thank You!

avdnowhere
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  • A records are tangential to mail, you seem to be thinking of MX records. And/or, CNAME records. [This guide by Zytrax](http://www.zytrax.com/books/dns/) covers A, MX, and CNAME record types, and explains how they work (and what they are used for). – iwaseatenbyagrue Apr 19 '17 at 16:37

2 Answers2

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Yes, it is. DNS is just the pointer.

Daniel
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Yes, it is generally possible and widely used. For mail servers I'd advise against it though.

The reason is that you can have only one reverse record per IP. If you send a mail from your test2.com domain the receiving mail server will try to resolve the ip address from the originating server, and it will resolve to mail.test1.com. In the best case this will result in a higher spam score, in the worst case your mail will be rejected because it doesn't match test2.com.

Choose one domain to use as master domain and set an MX record to mail.test1.com for your test2.com domain. You will have much less problems with your mail system that way.

Gerald Schneider
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