Re: [dmarc-ietf] Errors in RFC 8601, was Question about changes introduced by erratum

[John R Levine <[e-mail]>]

>> RFC5321.MailFrom is the address in the SMTP "Mail From" command
>
> So is RFC5321.MailFrom the Reverse-Path from RFC5321, or only the
> Mailbox part of a Reverse-Path? I would expect it to be the full
> Reverse-path, because

RFCs 2821 and 5321 say:

    Historically, the <reverse-path> was permitted to contain more than
    just a mailbox; however, contemporary systems SHOULD NOT use source
    routing (see Appendix C).

Source routes have been deprecated for 20 years.  We can forget about 
them.

> and a Return-Path field usually contains "<" ... ">", so it cannot be a
> plain Mailbox.

No, see RFC 2821 or 5321 sec 3.3.  The reverse-path is what's between the 
brackets, which means it's a mailbox or it's empty.

> By the way, an RFC5321 mailbox allows address-literals which are not
> covered by the right hand side of RFC8601's pvalue, and one cannot use
> the left hand side because of

I haven't seen an address literal in non-spam mail for over a decade 
either.  I'm pretty sure we can forget about them in A-R headers, too.

R's,
John