[Mailman-Users] change the sending email address

[Andrew Barter]

Hi,

I would like to change the email address that sends out the emails to a mailman list.

The emails come from the following address:
from=<kojoworld-admin at xxx.xxx.xxx.xxx>

where xxx is our IP address.

Because this is an IP address, a lot of the outward mail is getting bounced because of the following:
 Sender address rejected: Domain not found


Any help would be great.
Thankyou

Andrew