/SEND_TIMEOUT=minutes

    Optional. Defaults:

       DATA - 3 minutes
       INITIAL - 5 minutes
       MAIL - 5 minutes
       RECEIPT - 5 minutes
       TERMINATION - 10 minutes

    Maximum time between remote host acknowledgments of a particular
    SMTP command.

    If an acknowledgment is not received within the specified time,
    it is assumed that there are communication problems with the
    remote host. If the next delivery attempt takes place before the
    mail's delivery date, the mail is rescheduled for later delivery.