[Mailman-Users] mailman w/ fedora 7

I'm having a problem with only external email servers trying to send to my list. I can send email to the listserv list from the same box, but not outside. I keep getting the following error that I'm guessing either sendmail or something else on the box is blocking: Delivery to the following re

[Mailman-Users] multiple list in the To: field

I have 12 school list that at times I need to post the same message to ALL the list but the server rejects it thinking its spam. Is there an option that I can turn off or is there a way to send to 12 mailman list all at once? Thank you! -Tam --