David Newman writes:
Awhile back Stephen Turnbull suggested a terminology guide that included an MM3-specific definition of FQDNs.
I think that Mailman should use the usual definitions, but sometimes we have more restrictive implementations. For example, although we store the case sensitive form of email addresses, some checks for equality of email addresses are case insensitive even though local parts can be case sensitive at some hosts. That can be surprising, although frequently it's what users expect.
It's going to be hard to document all of these, but even listing some of them will probably help users diagnose issues for themselves, or suggest improvements.
Also in an MM3 context, I think it would be useful to distinguish between mail hosts and web hosts and domains (all in the general Internet sense) and mail domains and sites (in the MM3/Django/Postorious/Hyperkitty sense).
Yes, this is really complicated. Web hosts aren't too bad, although often www.example.com will be a CNAME for example.com and configurations like that, but Internet mail is quite a mess, what with CNAME, MX, and PTR at least being involved, and if you are doing signatures, all the stuff for SPF, DKIM, DMARC, ARC and more, not to forget that if you're actually sending and receiving mail you need to worry about distinctions among SMTP, LMTP, and SUBMIT, and all of the SSL/TLS versions. *sigh*
Not sure I fully understand these distinctions yet, but I can take a crack at it.
Just list them under "this stuff is really weird, watch out for dragons lest you be toasted from behind". :-)
Steve