This is a great mod. I get tons of users join, post for a while, only to then forget about the forum never to return. Periodically I would create a reminder newsletter for all members, manually creating a list of recent topics in an attractive html layout. But creating an HTML newsletter by hand every few weeks is such a bind. This mod essentially does that automatically which is wonderful.
My suggestions for improvement are as follows.
An option for all members to be joined by default. I have thousands of dormant members who no longer visit who I'd like to send it to and I'm sure they would appreciate getting it (if not they can click the link to immediately unsubscribe).
Instead of a list of Latest Posts it would be better to have Recently Updated Topics. Otherwise posts from a popular topic will swamp out all other topics. And have them grouped into their individual boards rather than all mixed together.
Can the subscribe/unsubscribe line be moved off the homepage as it just adds unnecessary clutter in quite a prominent position. Instead have a newsletter link among the existing menu items at the top, to link to a seperate page with the options to subscribe/unsubscribe.
Have a section in the newletter for a customised message to tell the recipients whats new since the last newslettter etc.