[exim] Perl integration - context?

    Is it possible with Exim’s Perl integration to create a reference that will last throughout a message’s delivery and then be reaped?

    I’d like to explore an flock-based lock for mail delivery that would allow an external process to suspend delivery by holding a lock on a designated path: if Exim/Perl does flock($fh, LOCK_SH) and fails EAGAIN, then Exim will defer acceptance of the message.

    When the flock() succeeds, ideally that flock()ed Perl $fh will last until delivery is done and then be reaped. Is it safe to store that in a Perl global, then call something else at the end of the routing that deletes/undefs that global? Or is there some cleaner way to give Exim such a reference and have Exim hold onto it for me until routing/delivery is over?

    Thank you!