[Mailman-Developers] layout

Hi folks,

Is it possible to change the layout of the message body in Mailman? (e.g. changing the left & right margin of the body message) Is it also possible to insert certain text into the body but _not_ header or footer?

Currently my Mailman 2.1 is running on my unix-apache-sendmail configuration very very well ...:)

-Yanuar-