Technical Wordpress Migration
My understanding is that while Listserv plugins exist for WP, none of them does what Yahoo did which
is post the incoming emails to a forum as well as forward them on to the members of the list.
For $200 + $2 per 1000 messages, I can create a local copy of Wordpress where I will create a board with all the old Yahoo groups
data and I then export that and you can import it into your live site.
I will include a CSV file of your users so that you can import them first.
Contact me here