Hans-Peter Jansen writes:

...

I'm willing to bet it will converge to "robust in practice" much faster than the previous design did.

I will take your word on that.

Why take my word when you can take my money instead? :-) Keep on with the porting project!

...

Patience and understanding of how opensource software development works, perhaps.

Okay, as already said, I'm sorry for sounding overly harsh.

Yeah, me, too. I actually saw Barry's and David's posts while composing and decided I didn't have much to add after all, but apparently I managed to send without noticing (bad Emacs! bad Emacs!) before deleting the draft. Sorry about that; you didn't deserve multiple reprimands.

Usually, when I report such problems nowadays, I add a patch proposal for fixing the issue, but these issues were overwhelming me. Needless to mention the complexity of the email package itself and my reluctance of studying RFCs.

The email RFCs are probably not worth studying. They're not only quite complex, on many points they are controversial. Leave that to us. ;-) Merely identifying problems (thanks for the test cases, by the way!) is a great contribution.