I have a problem which I think can be resolved by adding a ptr record. Email isn't working for xx@domain_a.com. I looked up the smtp issues on mxtoolbox.com which returned the following: SMTP Reverse Banner Check Reverse DNS FAILED! This is a problem..
When I look at the DNS settings, the mail, mail(x) etc records point to an ip address and adomain.net. I believe the email is sent from an external server so the solution would be to add a PTR record, correct? Where do I add this? Do I add this on the domain to point to the email, or should it be added where the email is sent from to point to my domains ip?