Mailing list server
 

Is there a program that could:
1) Received an email and forward it to a list of people
2) People can subscribe and unsubscribe to the list
3) If possible that will only forward email if it is only from a trusted list of email addresses.

I am not to bothered what OS it has to run on!

Thanks in advance

Tom

Mailman is pretty industry standard for this type of thing:
http://www.list.org