1. Switch to root user sudo su 2. Install postfix yum install postfix -y 3. Stop sendmail (installed on Amazon Linux by default) /etc/init.d/sendmail stop 4. Start postfix /etc/init.d/postfix start 5. Switch MTA from sendmail to postfix alternatives –set mta /usr/sbin/sendmail.postfix 6. Configure postfix to allow email for the same domain name to be received. […]