I have been having DNS issues since getting a different IP address about 5 days ago. MX Toolbox give a Reverse DNS fail while dnsstuff.com gives it a Reverse DNS authenticity: [Verified]
Now I know the real test is to wait for the client to send an email successfully that failed, but I am a little worried that it is an issue on my side. However, everything I read is that it is a ISP issue. All the DNS setting appear correct through ATT and I am getting a success from one site. Is the mxtoolbox wrong, or is there something I can check on my side?
I have a watchguard x750e firewall and an Exchange 2003 mail server.