How to send mail through Gmail On Ubuntu using postfix

Introduction

Postfix is used mail transfer agent that is used to send and receive emails. It is easy to install and configure on Ubuntu server.

In this tutorial, we will show you how to configure Postfix with Gmail on Ubuntu.

Prerequisites

Before you proceed, you will need the following −

• A running Ubuntu server

• A Gmail account

• A valid domain name that is configured to point to the server's IP address

Step 1: Install Postfix

In the first step install Postfix on your Ubuntu system. You can do this by running following command −

#apt-get install postfix -y

During installation, you will be prompted to select mail server configuration and there options. You should choose "Internet Site" and fill your server's domain name when ask.

Step 2: Configure Postfix

Once Postfix is installed, you need to configure it to use Gmail as a relay for all emails. Open the main Postfix configuration file by using the following command −

# vi  /etc/postfix/main.cf

Add the following lines to the end of the file −

relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous

Save and exit the file.

Step 3: Create a Gmail App Password

To use Gmail as a relay server, you need to create an App Password in Gmail configuration. This password is use to authenticate Gmail's servers for relaying emails. To create an App Password, you can follow tthis link.

Follow Below guide to Configure “Gmail App Password”

https://www.devopszones.com/2020/03/how-to-create-use-app-passwords-in-gmail.html

Step 4: Add Gmail Credentials in Postfix

Now that you have created an App Password, you need to add it to Postfix. Create a new file called "sasl_passwd" in the /etc/postfix directory by running the following command −

#vi /etc/postfix/sasl_passwd

Add the following line to the file, replacing "your-email@gmail.com"with your Gmail address and "your-password" with the App Password that you generated −

 [smtp.gmail.com]:587 your-email@gmail.com:your-password

Save and exit the file.

Now, use following command to hash the sasl_passwd file −

#postmap /etc/postfix/sasl_passwd

Step 5: Restart Postfix

Now restart Postfix service to apply the changes by using following command −

#systemctl restart postfix

Step 6: Test the Configuration

To test configuration, send an email using the "mail" commans, and replace "recipient@email.com" with the email address you want to send the email to −

#echo "Test email" | mail -s "Test subject" recipient@email.com

If everything is configured correctly, the email should be sent and received by the recipient.

Configure the Zabbix to send e-mail:

Email Received on Gmail.