[Mailman-Users] how to address bounceback spam?

[Ali, Saqib]

bounceback spam is becoming a problem for me.

spammers use the some email random email addresses in the From/ReplyTo
field and spam my mailman subscription address @
fde-subscribe at www.xml-dev.com. This causes "unknown command"
bounceback to some innocent email user who never sent any emails to
fde-subscribe at www.xml-dev.com

how can I address this problem? The IP block owner for my servers
wants a resolution ASAP.

saqib
http://doctrina.wordpress.com/