I have an Ubuntu-based Linode which hosts a few websites for Mavelous Web Design, and I'd like to set up and configure some mailing list software for some of my clients. I've already apt-get install'ed mailman, and attempted to follow directions, but none of the emails that the server says it's sending upon configuration of a list ever make it anywhere that I can tell.

If anyone has experience with either mailman or another similar piece of software for creating and administering mailing lists, I'd appreciate some insight.

Preferably, it'll have a web-based management system, allow multiple administrators per list, and be able to support multiple domain names on the same server without any hint in the admin side that there are other domains here.