[Dovecot] mdbox and pop3 locking

With mdbox, what does dovecot lock when "pop3_lock_session(pop3): yes"?

Specifically, I'm wondering if Dovecot LDA is able to deliver mail when a session is locked, if using mdbox, or if it will tempfail until the session is unlocked?

Thanks, Ken

-- Ken Anderson Pacific Internet - http://www.pacific.net