SSMTP – an alternative to sendmail for sending mail, allows you to configure sending via third-party mail servers.
To install in Ubuntu, use the command:
sudo apt-get install ssmtp mailutils
Next, open the /etc/ssmtp/ssmtp.conf file in any text editor (in the nano, press Ctrl+X to exit, y/n to save or discard changes):
sudo nano /etc/ssmtp/ssmtp.conf
Comment out all and set up as shown below for an example:
root=test@gmail.com mailhub=smtp.gmail.com:587 hostname=smtp.gmail.com:587 UseSTARTTLS=YES AuthUser=test@gmail.com AuthPass=password FromLineOverride=YES
If you use Google mail, you will probably need to allow “Untrusted applications” in the settings at https://myaccount.google.com/security.
Also open the /etc/ssmtp/revaliases file in the text editor:
sudo nano /etc/ssmtp/revaliases
And add:
root:test@gmail.com:smtp.gmail.com:587
Let’s try to send the letter to the specified address (after the command we will type the desired text and put a point for completion):
sendmail -v admin@example.com
Letters must be sent from the address specified in the file /etc/ssmtp/ssmtp.conf.