smtp-auth *external* to qmail-smtpd?

[frostman]

Hi all.

I'm considering setting up smtp-auth, as some of my users aren't comfortable with pop-before-smtp.

Having googled around a bit, it seems there's no qmail smtp-auth that doesn't have either significant bugs or significant features I don't need.

I was thinking, shouldn't djb's modular framework allow, even WANT, me to do smtp-auth as a separate job, as opposed to patching qmail-smtpd?

Has anybody heard of this being done?

thanks.