When you send an email through SmarterMail, you receive following error in bounc back email.
Remote host said: 550 Access denied - Invalid HELO name (See RFC2821 18.104.22.168)
- Login as admin
- Settings/General Settings/Server Info
- Set the hostname to 'mailserver.mydomain.xxx'
- Point an A record of 'server1' to the ip of your server
- Create a Reverse DNS PTR record for the server ip to resolve back to mailserver.mydomain.xxx