regex based groups and email address changing

[Daniel Berlin]

I have user groups based on regexes (like *.gcc.gnu.org)
If people change their email address, so that it doesn't match the 
regex anymore, are they auto-added to the approriate groups they used 
to be part of?
I've never seen a bug about it, so I assume they are, but i figured 
whoever implemented email address changing is on this list, and would 
know.

--Dan