Newsgroups: comp.protocols.tcp-ip
Path: utzoo!utgpu!watserv1!maytag!gamiddleton@watmath
From: Guy Middleton <gamiddleton@watmath.waterloo.edu>
Subject: Re: Is underscore legal in the local-part of an address?
In-Reply-To: <5E6FA41D7E3F40EAD8@baylor.BITNET>
Message-ID: <1990Jul23.215936.1584@maytag.waterloo.edu>
Sender: gamiddle@maytag.waterloo.edu (Guy Middleton)
Organization: University of Waterloo Software Commando Squad
Date: Mon, 23 Jul 90 21:59:36 GMT
Lines: 13

Mike Califf writes:

> At least one of the INTERBIT (Internet-to-BITNET) gateways is
> rejecting addresses which contain an underscore.  The postmaster
> at the gateway says that this is because his software correctly
> implements RFC821 which restricts addresses to letters, numbers,
> and hyphens.

I think he may be a bit confused.  The elements of the hostname should be
letter-digit-hyphen, but the local-part (anything left of the @) may be
anything at all, but, if it contains any special characters from the set
<>()[]\.,;:@" or control characters, they must be escaped by a \, or else the
whole local-part must be enclosed in quotes.