Load simmulator for testing qmail

[Amit Vadehra]

HI,
    I need to find a load simmulator that will pump mails to a
particular id or a set of ids that to check the the  load generated by
pumping that many mails at one point of time and how qmail handles it.
We need something that will pump mails of different sizes and types so
that we can test the total email infrastructure.
Qmail is on Linux ( redhat 5.4) . Can one write some kind of a script
that you do the same.
Please let me know at the earliest.
Thanks
Amit Vadehra