Emails from Mailman lists are shown as being sent "on behalf of" the mailing list

Introduction

Certain third party email clients will read the headers of messages sent from a Mailman list and show them as being sent "on behalf of" the name of the mailing list itself. This occurs when the Mailman service writes the sender header in an attempt to avoid losing bounced messages. To avoid this unwanted display, you can disable rewriting the sender headers.

Procedure

1. Navigate to "cPanel / Email / Mailing Lists" and select the option to "Manage" the list you wish to update.
2. Select "General Options" 
3. Find the option for include_sender_header and set it to "No." It is labelled with the following:
   "Should the Sender header be rewritten for this mailing list to avoid stray bounces? Yes is recommended."
4. Click on "Submit Your Changes" to apply the setting. Future messages will not rewrite the headers when sent.