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How can I use the identification method "message header"?

With this identification method, you can define specific headers for us to search within outgoing messages. If a message does not have these lines, it is blocked by the filter. This can help to prevent or better track spam without affecting other senders of the domain.

Step 1: Configuring the identity header in the EuropeanMX admin panel


Log in to the admin panel. You can find instructions in our FAQ article "How can I log in to the Admin-Panel (web interface of the filter)?".


In the "Outgoing" menu, click on the sub-item "Manage users".


Select "Edit" from the Domain Authenticating User's drop-down menu.


Select "Message Header" from the drop-down menu "Identification Method" and click on the button "+ Add New Identification Header".


In the "Header name" field, enter the header name that you are configuring (e.g. "X-AuthUser" for Exim/cPanel or "Received" for Postfix).

For the "Header Value" choose between the following two options:

  • Simple: The entire message header value is used to identify unique users who share this identification method
  • Adjusted: Specify a custom regular expression that is used to extract the identity from the message header value to identify unique users who share this authentication method.

Note: The individual regular expression must contain a group that represents the identity.


If you do not want to keep the part of the header after it has been edited by EuropeanMX, select the "Remove after editing" checkbox. If you want to keep the part, please leave the checkbox unchecked.

Please note: Depending on how the message header is created, it may contain information that you should not publish. For example, if the identification is based on the user's login ID, you should ensure that the "Remove after processing" option is checked.


Click on "Add".

Please note: If you have more than one identity configured, each identity will be processed in turn. If there are multiple headers in a message, EuropeanMX will always process the first header as the first one.


The setup at EuropeanMX is now completed. You can check the settings by searching for a sent message under "Outgoing" < "Logs" and viewing the "Identity" column. If you see the previously defined data in the column, the identification works correctly.

It is important to set up a good identification for your different mail streams in order to use this feature effectively.

There are many different message headers and identities that you can use. Below are a few examples:

  • cPanel:
    • Header name: X-AuthUser
    • Header value: Simple
  • cPanel:
    • Header name: X-PHP-Originating-Script
    • Header value: ^(.*?)\(.*$
  • PostFix:
    • Header name: Received
    • Header value: .*\(Authenticated sender: (.*?)\).*

Step 2: Setting up the identity header on your mail server

To enable EuropeanMX to check the identity header when sending a message, your mail server must be configured to automatically add the identity header when the message is transferred. Below we have put together a few sample configurations:

  • Microsoft Exchange:

To add individual lines in the message header, an XHeader transport agent must be created in Microsoft Exchange. For more information, please refer to the Microsoft KB article (

  • cPanel/Exim:

headers_add = X-AuthUser: $authenticated_id

headers_add = X-AuthUser: ${if match {$authenticated_id}{.*@.*}\
{$authenticated_id} {${if match {$authenticated_id}{.+}\

headers_add = ${if !eq{$original_domain}{$domain}{X-Forwarded-For: $original_domain}}

  • PostFix:

Please add the following line in your postfix to the file, if not already present

smtpd_sasl_authenticated_header = yes

This adds the line "Authenticated Sender" to the received message header.

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