Re: VGER's filters..

["H. Peter Anvin" <hpa@zytor.com>]

Followup to:  <20030404181054.GT29167@mea-ext.zmailer.org>
By author:    Matti Aarnio <matti.aarnio@zmailer.org>
In newsgroup: linux.dev.kernel
> 
> With Yahoo I had at first immense problems to get any email from them,
> as their SMTP email sender uses INVALID protocol:
> 
> <<-  MAIL FROM: <yahoo-dev-null@yahoo-inc.com>
> ->>  501 5.1.7 strangeness between ':' and '<': <yahoo-dev-null@yahoo-inc.com>
> When you read really carefully RFC 821 / 2821 syntax about that,
> you will see that it does not allow space in that place.
> Sendmail does, and that has forced others to extend the syntax alike.
> 

Sendmail, and a whole bunch of other mailers, have taken the more
liberal approach of allowing any RFC 822-compliant address in this
place (which is a *lot* more liberal than an RFC 821-compliant
reverse-path.)  This is consistent with the "be liberal in what you
accept, conservative in what you send" philosophy of network
interoperability.

I suspect in Sendmail it naturally falls out of using a single set of
canonicalization rules for all syntax.

	-hpa
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64