Matching A and PTR records
- Thread starter Spark
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jlandes
Verified User
Your A and PTR records should match for the IP address that is sending and receiving mail. Otherwise, your mail may be tagged as spam by some mail systems.
nobaloney
NoBaloney Internet Svcs - In Memoriam †
That depends on what you mean by match.
There needs to be a reverse DNS record (PTR record) for every IP# used to send email. It does not have to reverse back to domain name of the sender. But for example:
If 12.34.56.78 points to server.example.com, then there should be an A record for server.example.com pointing towards 12.34.56.78.
There can be many other A records pointing to 12.34.56.78, but there should not be more than one PTR record for 12.34.56.78, and it should point to one of those A records.
There is no requirement that the A record be for the hostname, but in shared hosting environments generally that's what shared hosting providers use.
Why? If you're using myhostingcompany.example.com as the A record, and you send email from mail.myhostingcompany.example.com, then your resellers, who sell hosting under their name, probably won't want their customers to see your company name in their headers.
That's why we use a generic domain name with a proxy registration for all our hostnames
.
Jeff
There needs to be a reverse DNS record (PTR record) for every IP# used to send email. It does not have to reverse back to domain name of the sender. But for example:
If 12.34.56.78 points to server.example.com, then there should be an A record for server.example.com pointing towards 12.34.56.78.
There can be many other A records pointing to 12.34.56.78, but there should not be more than one PTR record for 12.34.56.78, and it should point to one of those A records.
There is no requirement that the A record be for the hostname, but in shared hosting environments generally that's what shared hosting providers use.
Why? If you're using myhostingcompany.example.com as the A record, and you send email from mail.myhostingcompany.example.com, then your resellers, who sell hosting under their name, probably won't want their customers to see your company name in their headers.
That's why we use a generic domain name with a proxy registration for all our hostnames
.Jeff
Actually I was saying a PTR record and A record matching for the mail server.
so lets say the A record for: 75.123.24.100 is mail.myserver.com
does its PTR record also need to be mail.myserver.com in order to prevent it from ending up in spam boxes. Or can the reverse be for example 75.123.24.100.reverse.myserver.com
I never once asked if it needed to reverse back to the sender that would be pretty impossible being as many domains can be hosted on a single IP address.
I asked if the A record and PTR record needed to match for the outgoing mailserver, my question does not get any more clear. I am sorry my questions confuse you maybe it would be less confusing if I said since the server sends out mail from the primary server's IP address should the PTR record and A record for the hostname be exactly the same? Is that easier for you to understand?
so lets say the A record for: 75.123.24.100 is mail.myserver.com
does its PTR record also need to be mail.myserver.com in order to prevent it from ending up in spam boxes. Or can the reverse be for example 75.123.24.100.reverse.myserver.com
I never once asked if it needed to reverse back to the sender that would be pretty impossible being as many domains can be hosted on a single IP address.
I asked if the A record and PTR record needed to match for the outgoing mailserver, my question does not get any more clear. I am sorry my questions confuse you maybe it would be less confusing if I said since the server sends out mail from the primary server's IP address should the PTR record and A record for the hostname be exactly the same? Is that easier for you to understand?
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nobaloney
NoBaloney Internet Svcs - In Memoriam †
Thanks for the telephone call clarification. I think it should work.
Jeff
Jeff