Hello, I like some advice… We migrated from Domino to Exchange 2010 last December. We can send and receive emails from everyone except a domain in UK. My first reaction was to make sure nothing happened to my PTR record and etc… and everything matches. (Exchange server External IP to mail.domainname.com and vice versa).But it looks like my firewall is responding when this particular domain tries to a reserve PTR check. My question is, should I add my firewall IP address to my PTR record also: Exchange server External IP to mail.domainname.com and Firewall IP to mail.domainname.com? I don’t see a problem because I’m not changing my A record.