If you want to moderate your mailing lists you will need either the Action Email Roles module or the Rules module. The former provides a relatively simple action that sends an email to moderators when a new node of the type you chose for mailing lists, i.e., discussion, announcement, or comment is created. The latter is more flexible, allowing you to designate a different moderator for each mailing list, or to have some mailing lists that are moderated and others that are not.

I will not go into detail about setting up these modules; each is amply documented. A couple of points are important:

• You should make the moderator a member of each group s/he moderates.
• Set the feeds processor commands for each mailinglist and listmaster to make newly created nodes and comments unpublished. The confusion here is that you make a node unpublished by using status: 0 in the mailing list feeds processor, and you make a comment unpublished by using status: 1 in the listmaster feeds processor.

The workflow is straightforward. When an email is sent to the group mailbox an unpublished group content node is created, and when the email goes to listmaster an unpublished comment is created. The trigger or rule sends an email to one or more moderators. ideally the email at least contains a link to, if not the body of, the new node/comment.

Mailhandler was designed to permit a user to send commands back on a reply email, but I have not tried this recently. If a moderator sends a reply to the mailinglist's mailbox, i.e., group1@example.com, with status: 1 at the top of the body, it should make the node published. A reply to listmaster with status: 0 at the top should publish the comment. Again, I'm not sure this will work. In any case, the moderator can use the link in the email to go to the node/comment and change its status on the website.