Configure postfix

If this is a web server, make sure you changed MX record with dns provider to point to your server (or you will not be able to receive mail). I have modified the following is /etc/postfix/mail.cf:

myhostname = mydomain.com
myorigin = $myhostname
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost

Use http://pingability.com to check your DNS setup.