In the new version of sympa, there are a number of aspects of your list that are no longer user-customizable. However, you can still edit the following files by clicking on “Admin” and then clicking on “Customizing:”

• Homepage: HTML text to describe the list. It is printed on the right-hand side of the main list page.

• Description: This text is included in the welcome message for new subscribers and is the default homepage.

• Message Header: If this file is not empty, it is added as a MIME attachment at the beginning of each message.

• Message Footer: If this file is not empty, it is added as a MIME attachment at the end of each message.

• Deletion Message: This message is sent to users when you remove them from the list (unless
  you hit the quiet button).

• Subscribing Invitation Message: This is sent to people you invite for subscription.

• Welcome Message: This message is sent to new subscribers.

• Editor Rejection Message: This message is sent to people when you reject their posts.

• Remind Message: This message is sent to each subscriber when you click “Remind all subscribers.”

• Virus Infection Message: This message is sent to a user if a message they try to send
  to the list is infected with a virus.