Re: Browse other users personal messages
I don't think so.
Admins can use the "switch user" feature to become someone else, without knowing their password (by typing username in tiki-login_scr.php). But after, you need to logout and start over. (not fun, I know)
You could also check directly in the database. (via PhpMyAdmin)
Look for these tables:
messu_archive
messu_messages
messu_sent
M 😉