Please reccommend me an autoresponder

[neveremail]

Hi I need a server side autoresponder that will:

1. Reply to certain messages based on message rule settings - i.e if it has "specified word" in subject.
2. Can send more than one email when a message rule is met.
3. Can automatically send follow up messages.
4. Can add people to a mailing list and allow management of a mailing list.
5. Allow manual emails to be sent to mailing list.