Install Postfix server:
bash$ sudo aptitude install postfixand input these options:
Mail Server Configuration -> Internet SiteSystem Mail Name -> smartonline.comRoot and postmaster mail recipient -> sysadminOther destinations to accept mail for (blank for none) -> localhostForce synchronous updates on mail queue? -> NoLocal networks -> 172.16.110.0/8, 127.0.0.0/8Mailbox size limit (bytes) -> 0Local address extension character -> BLANKInternet protocols to use -> ipv4If you want to reconfigure the postfix, execute:
bash$ sudo dpkg-reconfigure postfixThe myorigin parameter specifies the domain that appears in mail that is posted on this machine.
myorigin = $myhostname (default: send mail as "user@$myhostname")myorigin = $mydomain (probably desirable: "user@$mydomain")The mydestination parameter specifies what domains this machine will deliver locally, instead of forwarding to another machine. The default is to receive mail for the machine itself.
mydestination = $myhostname localhost.$mydomain localhostAuthorized networks are defined with the mynetworks configuration parameter. By default, Postfix will forward mail from clients in authorized network blocks to any destination.
mynetworks = 127.0.0.0/8 168.192.0.0/24 (authorize local machine and the 192.168.0 subnet)The relayhost parameters specifies the method of delivering mail. By default, Postfix tries to deliver mail directly to the Internet.
relayhost = (default: direct delivery to Internet)bash$ telnet <IP> 25EHLOMAIL FROM: <from-email>RCPT TO: <recipient-email>DATAType message here.<Enter>The last line leaves DATA mode.