[adrian_b]

Actually the original qmail still works fine.

However it has some compatibility problems with modern practices, the most significant being that it does not know TLS.

Having to use TLS is the main reason for running a qmail fork instead of the original.

[eqvinox]

"works fine" and "has some compatibility problems" is a little bit of an oxymoron... I understand what you're trying to say, but that does mean it's essentially unusable, despite "working fine".