If you are like me, you have some Linux machines at home or a workstation which would benefit from relaying mail out for logwatch, owncloud emails, cron errors, or other reasons like perhaps a home mail server. If using Time Warner this is how to relay mail from home without being dropped or marked as spam!
Use this host to relay mail when on a TWC network: mail.twc.com
1. First, install postfix
sudo apt-get install postfix
If prompted, select internet site.
2. Next, edit the postfix config file
sudo vim /etc/postfix/main.cf
Locate the line which says relayhost = which should be blank by default. Change that to
relayhost = mail.twc.com
Save the file.
3. Finally, restart postfix
sudo systemctl restart postfix
Done. Mail will be delivered ok using TWC’s mail relay. No authentication is required if on TWC’s network.