I'm trying to learn more about classic, text based internet
infrastructure and protocols, which includes email and SMTP.

Which groups would be the best to ask about and discuss such things?

E.g., I'm curious about the differences between the various MTAs, how
and why to set them up in certain ways, etc.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)