Configure Smarthost SMTP Authentication on Postfix

My machine at home cannot send email using port 25, end up I got to do smart host SMTP authentication on Port 587 means your machine will connect to your public mail server, and from your public mail server deliver the email to recipient. Let’s do some simple Smarthost SMTP authenication on Postfix. The example is Postfix on Linux Ubuntu server.

Create Authentication Password File For Postfix

Create a password file which require authentication on your mail server.

Save the file and perform some simple permission settings.

Now you have done with SMTP server authentication configuration file.

Configure Smart Relay on Postfix

Fire up Postfix’s main.cf config file

Paste the config below on the bottom of the configuration

relayhost is the your server address and with port 587, in case your ISP is blocking port 25. You can use either plain password authentication or SASL authentication, depend on what type of authentication does your server support.

Save it and reload Postfix Service

Perform the testing on your newly configured SMTP Smart Host Authentication

Check on the mail server log on delivery status.

If the status is sent, it means your smart host is working well.