Hello,

If DNS report gives this warning :

"Mail server host name in greeting :
WARNING: One or more of your mailservers is claiming to be a host other than what it really is (the SMTP greeting should be a 3-digit code, followed by a space or a dash, then the host name). If your mailserver sends out E-mail using this domain in its EHLO or HELO, your E-mail might get blocked by anti-spam software. This is also a technical violation of RFC821 4.3 (and RFC2821 4.3.1). Note that the hostname given in the SMTP greeting should have an A record pointing back to the same server. "

That time it means that the ip of the hostname of the server is diffrent from the A record of that domain.
For eg. the eth0 ip of the server is 67.18.4.2 & the A record of a doman is 67.18.4.4.
If we change A record IP then it will not display the warning.

Regards,
Anil Chandaliya