YahooGroups replacement???

YahooGroups functionality includes both LISTSERV and FORUM capabilities. Listserv

I have several clients who would be interested in similar functions (i.e., a complete replacement for YahooGroups). MailMan3 suite has been available for a couple of years now, but requires “containers” or Ubuntu for proper installation of all functionality.
There are two classes of functions that are needed for a YahooGroups replacement:
1) First is using the WordPress site to read/search previously sent messages. This makes it possible to read all messages, regardless of when you “subscribed”. This is the “archive” or “forum” capabilities of some WordPress applications/sites such as bbPress and buddyPress.
2) Next is using WordPress site to send SEND new messages to the group. This allows the case where the “subscriber” never uses email to read messages, and has (in fact) turned off sending of group messages to their email address. They ALWAYS login to the site and read messages while on-line, as in the case of “forum” software such as bbPress and buddyPress.
After using the free version (v1.6.7b) for a while, some “missing features” become apparent, including making it possible for the ID=1 (admin) account to always be a member of ALL mailing groups. i.e., they should always be able to send a message to any mailing group, and they should (perhaps conditionally) receive a copy of any message that is sent to ANY mailing group; whether they are moderating the group or not with the premium version.
Other “group” functions, on a per-group basis: Attachments are permitted, or not.
Members can/cannot hide their email address.
Membership is by invitation-only, or via a “public” register URL.
Moderation: messages require approval before distribution to the group, or being visible within the group.
All members can post, or not.
A daily or weekly “digest” (or summary) of messages can be sent to each subscriber who elects to receive it, or not. [Some folks elect to receive “the daily digest” AND also to NOT receive the individual messages. That way they can know that things are happening within the group, and can then simply login to the sit to read messages, or follow the permalinks in the digest to go to each individual message that is in the WordPress archive-of-messages.

The page I need help with: [log in to see the link]