Rudy -- FAX messages are indeed lengthy -- any image format is. I'm not
sure, but I think a typical faxed page is about 20K. I'm sure it will
put a strain on some mail queues, but frankly I see that as part of the
price of progress.
If disk space for mail queues is a real problem, you might want to look
into using the "message/external-body" construct for your faxes. In
that case, you'd be mailing around a *pointer* to a fax rather than the
fax itself. Only trouble is that you'll then need to implement some
kind of garbage collection or time-out scheme for the pointed-to faxes.
You pays your money & you takes your choice...