How to Setup Mail Forwarding in Postfix

Postfix is a popular open-source mail transfer agent (MTA) used on Linux systems to route and deliver email. One of the many features it offers is email forwarding, which allows you to forward incoming emails to another email address automatically. This article will guide you through the process of configuring email forwarding in Postfix.

Installing Postfix

Before configuring email forwarding, ensure that Postfix is installed on your system. If it’s not, you can install it using the package manager for your Linux distribution.

• For Debian/Ubuntu:

  sudo apt-get update 
  sudo apt-get install postfix 
  

• For CentOS/RHEL:

  sudo yum install postfix 
  

Configuring Email Forwarding in Postfix

Postfix allows you to configure email forwarding using the virtual alias maps. These maps define the email forwarding rules for the system. To configure email forwarding in Postfix, follow these steps:

Step 1: Edit the Postfix configuration file

Open the main Postfix configuration file /etc/postfix/main.cf in a text editor:

sudo nano /etc/postfix/main.cf 

Locate the virtual_alias_maps directive in the configuration file. If it’s not present, add the following line to the end of the file:

This configuration line tells Postfix to use the /etc/postfix/virtual file as the source of virtual alias maps.

Step 2: Create and edit the virtual alias map file

Create the virtual alias map file /etc/postfix/virtual if it doesn’t exist:

sudo touch /etc/postfix/virtual  

Open the virtual alias map file in a text editor:

sudo nano /etc/postfix/virtual 

Step 3: Add email forwarding rules

Add the email forwarding rules to the virtual alias map file using the following syntax:

Where source_email@example.com is the email address that will have its incoming mail forwarded, and destination_email@example.org is the email address where the mail will be forwarded.

• You can add multiple email forwarding rules, one per line:
  user1@example.com user1.forward@example.org user2@example.com user2.forward@example.org

  1 2	user1@example.com user1.forward@example.org user2@example.com user2.forward@example.org

• Forward support@example.com emails to rahul@myemail.com and admin@myemail.com
  support@example.com rahul@myemail.com admin@myemail.com

  1	support@example.com rahul@myemail.com admin@myemail.com

• Forward any email sent to @example.com domain to rahul@myemail.com. Also forward any email sent to @example.net domain to rahul@myemail.com as well as admin@myemail.com
  @example.com rahul@myemail.com @example.net rahul@myemail.com admin@myemail.com

  1 2	@example.com rahul@myemail.com @example.net rahul@myemail.com admin@myemail.com

Step 4: Update the virtual alias map database

After adding the email forwarding rules, save the file and exit the text editor. Next, update the virtual alias map database using the following command:

sudo postmap /etc/postfix/virtual 

This command generates a database file named /etc/postfix/virtual.db that Postfix uses to look up the email forwarding rules.

Step 5: Reload Postfix

Finally, reload the Postfix configuration to apply the changes:

sudo systemctl reload postfix 

Testing Email Forwarding

To test the email forwarding configuration, send a test email to the source email address you configured for forwarding. If everything is configured correctly, the email should be forwarded to the destination email address automatically.

Conclusion

Configuring email forwarding in Postfix is a simple yet powerful feature that can help you manage your email more efficiently. By following the steps outlined in this article, you can easily set up email forwarding in Postfix and route incoming messages to the desired destination. This capability is especially useful when consolidating multiple email accounts or redirecting messages to a different email address.