That's good..thanks for this gem. The list grows yet again...
Not gonna try it (out of politeness, in case it actually does work) so I'll take your word.
You don't need to actually send a message. Just click on the link and then
hover above the link to "Send private message", and see the address that
shows up. You can even click on it and see the same in the To: field of the
message that opens.
Jive usernames have more restrictions then Adobe IDs. As a consequence some stuff is broken. Both Adobe and Jive are aware of that. It is unlikely to get fixed anytime soon unless you can demonstrate it is a security risk.