Current DNS setting: (MX: abc.com) - Broadband Line 1
MX 10: mail1.abc.com
mail1.abc.com = (A Record and PTR) 192.168.0.1
We have added new broadband Line 2 for internet connection redundant. Line 2 will pick up the mail server sent out job if Line 1 is down.
For Broadband Line 2, what PTR setting is good for us?
1. MX 20: mail1.abc.com
mail1.abc.com = (A Record and PTR) 10.10.10.1
2. MX 20: mail2.abc.com
mail2.abc.com = (A Record and PTR) 10.10.10.1
For PTR checking, it is really check "domain name" or "A record"?