I had planned to 'get around to his issue' until today when somebody send a message with a 63MB *.avi attachment (that's not a typo). It crashed the Outlook Express account/mailbox files on the Win 98 client box... it took me several hours to find the problem and fix it.
I mention that to make the point that maybe this is more than a 'nice-to-have' feature... I'd vote that the based e-smith installation be configured with a max message size (my vote would be subject to recount-of course).
Anyway here's the fix I used:
1) log on as root and create a filenamed 'databytes' containing one line with a value for the maximun size message (including attachments). For example, for a 2MB maximun do the following.
cd /var/qmail/control
echo 2048000 > databytes
2) restart qmail-smtpd
/etc/rc.d/init/qmail-smtpd restart
That's all (of course you'll want to properly package/template this according to the e-smith architecture guidelines).
Hasan