Email Only Discussions with Archive in Groupsite

I really need to have a feature where my group members (and separately the subgroup members) can send, read and reply to group messages using only their email - without having to go into the Groupsite. The emails should be in searchable archive on the groupsite. If this feature was there, I could justify a much larger investment of time and expense into our new groupsite. For now, I'm having to use Google Groups for the email based discussions and the groupsite for the files, profiles, blogs, etc.

Let me be clear - the group and subgroup discussions are at the heart of what my teams need for collaboration and that really needs to be integrated into the groupsite.

I like the clean interface of Groupsite.com and the many other features it provides. I must admin that I'm going to have to continue to look for a solution that has what I need. Google Groups used to have it - email discussions with a searchable message archive plus file storage, but the file storage was within the groups was eliminated in January of this year. I also prefer the ad-free user interface that the paid version of Groupsite offers - which is why I'm not in favor of Yahoo Groups (although it may come to that).

Thanks for listening,

--- Mic