I/we need to find out exactly what we need. We may want to do this through email-test.python.org (no-existent, for example, python.org is the relevant part, or maybe a private domain of someone's), but we have to be careful that it doesn't conflict with other uses.

email-test.python.org sounds apt. And since you think its good we could ping Mark about the same. Also, since its for our interop, we will be freeing it up again after the testing period ( something along the line of a few months ) making it available again.

I think that would need to be shortened, but mailauth would work and has a good rhythm. :-) Of course it may be "taken".

Perfect! I checked PyPI and didn't find any such packages. So at least till now no one has laid claim to it on PyPI though "taken" might mean other things I understand. (Still, the doubt remains whether the original author would like to get the name changed to something different. )

Yes, but Murray's OpenDKIM is a C library, and I expect OpenArc is too. I don't think we should be using a C library because we're not...

In any case, the more independent implementations the better.

Yes, right. I somehow missed that C fact. I'll like to see the code once its out, and see the approach used. Not for our purposes, but just curious :)

Aditya