Overview

sSMTP - a simple and lightweight MTA used to deliver mail from a computer to a mail hub (SMTP server) using Gmail SMTP servers. Unlike Exim4, it does not receive mail, expand aliases, or manage a queue.

Requirements

First you need to stop sendmail if it is installed:

service sendmail stop chkconfig sendmail off

Add the CentOS EPEL repository:

Download and install epel-release-6-8.noarch.rpm:

EPEL Current Version:

wget http://ftp.astral.ro/mirrors/fedora/pub/epel/6/i386/epel-release-6-8.noarch.rpm rpm -Uvh epel-release-6-8.noarch.rpm yum update

Install and Configure sSMTP

yum install ssmtp

Edit /etc/ssmtp/ssmtp.conf:

FromLineOverride=YES root=username@gmail.com mailhub=smtp.gmail.com:587 UseTLS=YES UseSTARTTLS=YES AuthUser=username AuthPass=[we suggest creating an app password with gmail 2 step authentication](http://support.google.com/a/bin/answer.py?hl=en&answer=175197).

Change to default MTA

Usually we have sendmail as the main MTA, we need to change it:

alternatives --config mta select /usr/sbin/sendmail.ssmtp.

Enjoy.