I currently run my site on WordPress with Wishlist installed to manage members of my network. I want to bring onto my site a suitable mail list option for my members to use, instead of an external service. This is what I perceive is needed:

• Messages to be archived so that members can view past messages at any time they login
• Messages can be sent from any member to entire list via email (as in yahoogroups)
• Multiple lists able to be set up for smaller groups (as can be done in ning)
• The main list to have the ability to grow to well over 1,000 members
• The ability to send email from Outlook or any other program without having to login to the system (as in yahoogroups – ning doesn’t let you do this)

I want to be able to run the mail list on my own server and under my own domain name rather than use an external service.   However, if there is potential for webspace or bandwidth problems, I do need to know about that.

What can you recommend?