Re: [Extra] Martin Duke's No Objection on draft-ietf-extra-imap4rev2-25: (with COMMENT)

[Bron Gondwana <[e-mail]>]

On Sat, Jan 23, 2021, at 15:57, Martin Duke via Datatracker wrote:

(I know the answers to these!)

> 2.3.1.1 what would happen if the UID approached 2^32 due to a lifetime of spam
> or something? The server can increment the validity value, but doesn’t that
> make earlier email unreferenceable except via sequence number?

Sequence number is even less persistent - but when you increment the UIDVALIDITY you can renumber the UIDs for everything, so you'd just start at 1 and reid all the existing records.  So they'll be referenceable by their new UIDs next time the mailbox is selected.

And (plug) if the server implements RFC8474 (object ids) then a client can even tell that it's the same email and not need to fetch the content again, even after a UIDVALIDITY change.

> 2.3.2 In the $Phishing definition, do you mean the user agent SHOULD (in caps)
> display an additional warning message?

This definition is copied from the IANA registry for keywords:

https://www.iana.org/assignments/imap-jmap-keywords/phishing/phishing-template

I'm not sure there's any point in changing the text to be different from the IANA registration just to make it capital SHOULD.  It's unlikely to change anybody's behaviour on reading this document.

> 4.1.1 the last statement, “ the "*" value for a sequence number is not
> permitted.”, is oddly placed, enough that it almost reads like a typo where you
> meant UID. A clearer statement might be “The ‘*’ value is permitted for UIDs
> but not sequence numbers.”

No, that would be an incorrect statement.  The phrase "UID set" is a definitional term which means:

* a sequence set;
* that references UIDs, not message numbers; and
* that consists only of numbers, not the magic '*' character (which can change value as new messages arrive)

You can have a "sequence set" which references UIDs and does contain '*', but then it's not a "UID set" any more by definition.

Cheers,

Bron.

--
  Bron Gondwana, CEO, Fastmail Pty Ltd
  [e-mail]