Freakin may be on to something here.
Kerowo, brings up a good point about someone else (you) managing the passwords. You could let
president@organization.com choose his own password but he would be required to let you know what it was. Then when Joe Smoe takes over the prez position and needs the
president@organization.com email addy you just log in and change the password to something of his choice. Now the former prez is locked out and you still have access to the new acct. I really think that might be the easiest solution here.