Although the Postfix sendmail function will work out-of-the-box on an aMiSTACX deployment, here are some tips in case you run into issues. Set the main.cnf to IP4 for the interface protocol sudo nano /etc/postfix/main.cf inet_protocols = ipv4 Make sure your hostname is the name of your domain. e.g., example.com sudo nano /etc/hostname Set the main.cf… Continue reading AWS EC2 Postfix Email Configuration Tips