Configure Zimbra Server for Catching All Incoming Emails via Another Application

Are you managing a Zimbra server and want to redirect all incoming emails to another application for processing? This can be achieved by configuring a catch-all email solution. One approach is to use a simple Postfix server to handle email routing. This article will guide you through the process, ensuring your Zimbra server is set up properly to meet your needs.

Step 1: Installing Postfix for Catch-All Emails

If you prefer to utilize a Postfix server for catching all incoming emails, the first step is to install it. Postfix is a high-performance mail transfer agent that can act as a robust mail server or a mail delivery agent. Its simplicity and reliability make it a popular choice for enterprise solutions.

HERE IS HOW TO INSTALL POSTFIX ON A UBUNTU SYSTEM:

sudo apt-get update

sudo apt-get install postfix

During the installation, follow the prompts to select the organization name (domain name) and specify the mail server hostname. For a catch-all email setup, choose the Internet Site option and provide an postmaster address.

Step 2: Configuring Postfix for Catch-All Emails

Once Postfix is installed, you need to configure it to catch all incoming emails and forward them to your preferred application or script.

EDIT THE MAIN CONFIGURATION FILE:

locate and modify the mydestination parameter. Adding a @all entry will help catch all emails sent to the server.

mydestination  localhost, , @all

ADD A RELAY MAP ENTRY TO FORWARD ALL EMAILS TO YOUR APPLICATION:

relay_recipient_map  hash:/etc/postfix/relay_recipients

CREATE THE relay_recipients FILE:

echo "postmaster   "  /etc/postfix/relay_recipients

CREATE A HASH DATABASE FOR THE RELAY_FILE:

postmap /etc/postfix/relay_recipients

RELOAD POSTFIX TO APPLY CHANGES:

systemctl reload postfix

Step 3: Configuring Zimbra for Email Delivery

After configuring Postfix to catch all emails, you need to ensure that Zimbra is set up to deliver emails using Postfix as the transport layer. This involves configuring Zimbra to pass incoming email traffic to Postfix for processing.

EDIT THE ZMCFG.XML CONFIGURATION FILE:

LOCATE THE zimbraMtaSmtpConnectionSocketListen AND zimbraMtaSmtp inetsocketlisten SETTINGS. SET THE LISTEN ADDRESS TO THE IP ADDRESS OF YOUR SERVER:

zimbraMtaSmtpConnectionSocketListen  your_server_ip_address:smtp_port

ANNOTATE THE ZMCFG FILE:

zmprov ma zimbraServerName zimbraMtaSmtpConnectionSocketListen your_server_ip_address:smtp_port

RESTART ZIMBRA:

/opt/zimbra/bin/zmcontrol restart

Step 4: Testing the Configuration

To ensure everything is working correctly, test your configuration by sending an email to a non-existent email address on your server. The email should be caught by Postfix and forwarded to your application or script.

USE THE telnet COMMAND TO TEST:

telnet your_server_ip_address 25

USE THE mail COMMAND TO SEND TEST EMAILS:

mail -s "Test Email" someemail@

Check your application or script to confirm that the email is being processed correctly.

Conclusion

By configuring a simple Postfix server to catch all incoming emails and forward them to a specified application or script, you can effectively manage your email traffic and improve the overall functionality of your Zimbra server. This approach provides a flexible and scalable solution for handling email processing and integration with other applications.

References

Postfix Configuration Parameters Zimbra Administration Guide