Postfix

Using MailMum with Postfix is pretty straightforward. You can use MailMum with Postfix through RBL (Real-time Blackhole List) technology.

Step 1: Add MailMum as RBL Client to Postfix

All configuration for Postfix is done in the main.cf file. You can find this file in /etc/postfix/main.cf or /etc/postfix/main.cf.default. Open the file in your favorite text editor and add the following lines at the end of the file:

smtpd_client_restrictions =
    reject_rbl_client <uuid>.in.mailmum.io,
    permit

Replace <uuid> with your MailMum UUID. You can find your UUID in the MailMum Dashboard.

Step 2: Hide the MailMum UUID

Your MailMum UUID should be kept private so that it is not abused by others. To hide the MailMum UUID from the, you should use the following configuration.

Create a new file /etc/postfix/rbl_reply_map and add the

<uuid>.in.mailmum.io    $rbl_code Service unavailable; $rbl_class [$rbl_what] blocked using in.mailmum.io ${rbl_reason?; $rbl_reason}

Note: Replace <uuid> with your MailMum UUID.

Optional: You can customize the message that is returned to the sender. We recommend adding some information regarding the MailMum System so the sender knows why the email was rejected and where he can get more information.

Add the following line to the main.cf file:

rbl_reply_maps = texthash:/etc/postfix/rbl_reply_map

Step 3: Check the Postfix Configuration

After adding the configuration, you should check the Postfix configuration for errors. You can do this by running the following command:

sudo postfix check

If it is incorrect, you will see an error message. Please check whether the UUID in the main.cf file is correct. If you can't find the error, please contact the MailMum support team.

Step 4: Reload Postfix

After adding the configuration, you need to reload Postfix to apply the changes. This is done by running the following command:

sudo postfix reload

If you are using SystemV, you can use the following command:

sudo service postfix reload

If you are using systemd, you can use the following command:

sudo systemctl reload postfix

Step 5: Test the Setup

To test the configuration, you can send an email to your server from an email address using an external E-Mail Service like Google Mail or Outlook.com.

If the setup was successful, the email should be delivered by Postfix and you should see an entry in the MailMum Dashboard.

Note: If you don't have any block entries in the MailMum system, MailMum behaves like a monitoring system. It only logs the requests from your Postfix server and enhance them with additional information.