I'm assuming that not everyone on this forum has listed their email addresses so contacting them that way is impossible. If you're attempting to clean up a database of non or nearly non-partcipating members then contacting them through the forum is, well, silly.
So, I would agree with Gary: there really is no way to contact them.
I lurked on this forum for months before joining any discussions mostly because I wanted to learn everything I could about this car before & after purchasing it. In addition, I wouldn't of felt comfortable adding my 2 cents worth if I first, was a complete idiot about our common love & second, if I didn't think the people that populate this forum were worth a dam_.
I think we should remove those "members" that are no longer active. If we whack a member who still occasionally participates well then he/she can always re-sign. There is an alternative. It's not like we're preventing them from ever rejoining, should they choose to do so.
Zappa has a valid point pertaining to those who post just for the heck of it (like yours truly) & those who are looking for some meaning. In that case though, they can still lurk.
By the way, Zap, he really is dead, more's the pity..........