Mail server load testing

[Dave Teske]

Does anyone know of any apps that can do load testing on mail servers. I've
seen a bunch that do web server load testing but none for mail servers. I've
got our server on a tiny (486 w/P90 upgrade chip & 24mb ram)box and I'd like
to see how much load it'll handle before I go scrounging for a replacement.

Thanks
--Dave