Editing the "only members can send messages" text

Since posting to my list is only allowed for members, I sometimes get the occasional error message where spammers have tried to send their junk but have been blocked. 
So what I (the list-owner) receive is an error message with their spam and apparently what Majordomo spits out at them. 
It's enclosed below, and I was wondering if it's possible to edit this file as some addresses in it need changing:
 
------------------------- start ----------------------------------
The message below, which you sent to [email protected]
is being returned to you, as only members may send messages.

If you believe you are a member, it is possible that you subscribed
to the list from a (slightly) different address/account than the one
you used when sending the message. You may only send messages using 
exactly the same address/account you used to subscribe to the list.

To subscribe to the list send the following message from the same 
account/address you are currently using:

  subscribe LISTNAME

to the address:

  <[email protected]>

If you ever need to get in contact with the owner of the list,
(if you have trouble subscribing, or have questions about the
list itself) send email to <[email protected]> .
This is the general rule for most mailing lists when you need
to contact a human.
------------------------- end -------------------------------------


Hallvard