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Re: [ietf-smtp] Valid RFC5322 address

Viktor Dukhovni <ietf-dane@dukhovni.org> Mon, 04 May 2020 19:09 UTC

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From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Date: Mon, 04 May 2020 15:09:17 -0400
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Subject: Re: [ietf-smtp] Valid RFC5322 address
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> On May 3, 2020, at 11:57 AM, John C Klensin <john-ietf@jck.com> wrote:
> 
> You also need to be very careful with the "." following the
> colon.  I haven't looked carefully enough at the syntax today to
> have any confidence how that would be handled with the
> Dot-string production -- you might have to quote the whole
> business to make it valid.

Unquoted "." is only valid in a dot-atom, and so:

	first.last@example.org
	/////.////@example.org

are both OK, but

	"/../"@example.org
	".///"@example.org
	"///."@example.org

all need quoting.  So long as both characters around the "." are "atext",
the "." does not force quoting of a local-part that would not otherwise
require quoting.

In this case, given that the ":" forces quoting, the "." requirements are moot.

-- 
	Viktor.

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