[Email-SIG] API for email threading library?

[Bill Janssen]

Some input from Mark Crispin (who wrote that bit about message-ID
normalization in RFC 5256):

> no-fold-quote does not exist in the current specification (RFC 5322)
> [which obsoletes 2822 - wcj].
> 
> I don't know why you think that the brackets should be removed in
> no-fold-literal. The brackets indicate that the contents are a literal IP
> address as opposed to a domain. The fact that 10.20.30.40, as opposed to
> [10.20.30.40], is parsed by some people as an IP address does not
> necessarily mean that it is (I'll laugh when the first all-numeric TLD is
> created!). Now, in the modern day of RFC 5322, this isn't a domain at all
> but rather an id-right.
> 
> People can flame at some length whether bloop at 10.20.30.40 and
> bloop@[10.20.30.40] are the same message-ID. My guess is "no".
> 
> The bottom line here is whether that text about normalized message ID has
> any particular meaning in the context of RFC 5322 as opposed to earlier
> versions of header syntax that used local-part at domain for message-id.
> IMHO (and I wrote that text!) I would treat it as advice on how to treat
> warts from the past rather than how to move forward.
> 
> That is, once upon a time, it was necessary to treat:
>
> Message-ID: <"bloop"@grok.this>
> 	and
> Message-ID: <bloop at grok.this>
> 
> as the same thing. This was a protocol wart and I'm glad to see it
> declared obsolete. I wouldn't flame anyone who decided that strcmp() is
> the one and only way to compare Message-IDs. I daresay that's what most
> implementations did anyway even when RFC 822 was king.

So, stripping double-quotes on the left side stays, stripping brackets
on the right side is a no-no.

Bill