I've recently added an SMTP forwarding component to qpsmtpd, so now you can use qpsmtpd without a qmail installation, and simply forward the SMTP session onto your real SMTP server, just using qpsmtpd as a gateway. It makes me wonder if Ask shouldn't change the web site to say that qpsmtpd is an SMTP server written in perl, rather than a qmail-smtpd replacement...
qpsmtpd needs more advertising. It's simply a kick ass project, and the code is really nicely written which makes it a joy to hack on. Nice work Ask.