Limit outgoing mail limit before send

[¶Âlh]

Hi all
Is there any method to avoid to send mail if the mail size is over a
preset limit?
If I set it in Exchange, the mail will first send to Exchange server and
check the size.
Any method to check the size before send to server?
I got this problem since the connection speed is slow, not like local
100m network.
Exchange server and the client Outlook XP PC is far away, connect with a
64K line only.

Thanks