In the LowEndSpirit, we tend to look for resource-efficient alternatives. Here is an alternative to use instead of Postfix, Sendmail, or Exim.

Often when installing and running a web application or script you need an SMTP server to send an email, rarely there is the need to receive any email. It works equally well using ssmtp, which also is simple and fast to install. It takes two minutes to install and configure.

RedHat, CentOS7, Fedora

yum install ssmtp

If you receive a “Package ssmtp is not available” error, you’ll need to install EPEL on your machine with the following command:

yum --enablerepo=extras install epel-release

Once done, you’ll be able to install ssmtp using the above command.

Ubuntu, Debian

apt-get install ssmtp

The configuration is done in the /etc/ssmtp/ssmtp.conf and there is only a couple of settings to change:

Mailhub
The mail server you must send mail through (relay). In this guide we will use GMail smtp Server.
From Line Override
Set to YES to allow the use of others choose from addresses other than the system itself.
AuthUser
The username or email adress on the account used to login to gmail.
AuthPass
The password for above account
UseSTARTTLS
Set to Yes to use TLS when connecting to the SMTP server.

## Config file for sSMTP sendmail
## The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=postmaster
# The place where the mail goes. The actual machine name is required no
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=smtp.gmail.com:587
AuthUser=name@gmail.com
AuthPass=YourtopSecretPassw0rd!
UseSTARTTLS=YES 
# Where will the mail seem to come from?
#rewriteDomain= 
# The full hostname
hostname=debianVPS.local 
# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: 
addressFromLineOverride=YES

No reboots required.

To use ssmtp with the PHP mail() function, you have to edit the sendmail_path parameter in php.ini to something like this:

sendmail_path = /usr/sbin/ssmtp -t

You have no open ports, everything just works!

Even if it is too late when someone else logs in as root on your server, it is good to know that NOW is the time to get working on your security.

To setup email notification, login to your server as root.
Edit .bashrc

editor .bashrc

add the following line at the end, changing “ServerName” to the hostname of your server and “email@thisaddress.com” to your own email address.

echo 'ALERT - Root Shell Access (ServerName) on:' `date` `who` | mail -s "Alert: Root Access from `who | cut -d"(" -f2 | cut -d")" -f1`" email@thisaddress.com 

!NOTE! - Take notice of the ` in the code block. Sometimes when copying code from a webpage, these small characters will mess up when pasted.

Save and exit your .bashrc.

Next time someone, hopefully you, logs on as root, you will get an email about this.

This can be done for any user, you only have to make sure that the user can email out from your server.

Quick Tip: Use the guide here to install and configure a Low Resource SMTP Server.

Would like it to be on pay as you go model if possible

Thanks