Hi.. i am testing centos6.3 and have configures it as a mail server. I have installed Postfix, Dovecot, and roundcube most of the things are working ok. I can receive mails from google, yahoo and from my domain. I can only send mail to my domain. when i send mail to google or yahoo i see the log says "Connect to smtp-gmail xxxxxx -- connection refused". I tested my smtp in mxtoolbox.com and it says "SMTP Reverse DNS Mismatch". From online dns tools when i do mail.mydomain.com i get my ip 220.127.116.11 (not real) and when i do 18.104.22.168 i get mail.mydomain.com and my smtp banner provided by postfix is mail.mydomain.com (found using telnet my server). What am i missing? my guess is DNS issue?? Reagards.