As of yesterday without warning my Blackberry (9000) cannot send e-mails. It can reply to ones sent (on the several mailboxes & BES Exchage acct).
The user list also won't autogenerate or offer options of auto-lookup. It usually defaults to the Desktop account and varies depending on the user I'm sending to but even that has disappeared!
I've also re-activated my Blackberry onto BES too!