4.5. Why don't the footers show up on some list messages? (Mailman 2.0.x)
This is a known problem and limitation with Mailman 2.0. Mailman 2.1. fixes this area.
Under Mailman 2.0.* footers are added by appending a text block to the end of each message. This works well for plain text messages. It does not work for MIME messages as the footer does not lie within the MIME structure of the message.
Converted from the Mailman FAQ Wizard
This is one of many Frequently Asked Questions.