On Thu, 2007-10-18 at 12:27 -0400, Charlie Brady wrote:
> qpsmtpd currently accepts <""@domain.name> as a recipient address, and
> (unless rejected for some other reason) will queue to @domain.name.
> I don't think conforms with RFC2821, and I don't think it's ever needed.
RFC 2821 says that local-part (see below) may only be interpreted by the
host receiving mail for domain (see below) and only gives a maximum of
64 characters (no minimum). RFC 2822 says that "" is a valid
local-part. Whether it is needed or not, I have no idea.
Bernstein gives an example with null local-part:
http://cr.yp.to/im/address.html
which may only be written using "" according to RFC 2822.
RFC 2822, Section 3.4.1
addr-spec = local-part "@" domain
local-part = dot-atom / quoted-string / obs-local-part
And:
dot-atom = [CFWS] dot-atom-text [CFWS]
dot-atom-text = 1*atext *("." 1*atext)
So dot-atom requires at least on character (as does obs-local-part) but
quoted-string does allow "":
quoted-string = [CFWS]
DQUOTE *([FWS] qcontent) [FWS] DQUOTE
[CFWS]
(see: RFC 2234 for ABNF). The meaning of * is a*b where 'a' and 'b' are
digits which default to 0 and infinity so "" is a valid
quoted-string ... so it does conform ...
--
--gh
