On Mon, 13 Sep 1999, Randy Bush wrote:
> exim has a lot of stuff like
>
> helo_strict_syntax option
>
> Option: helo_strict_syntax
> Type: boolean
> Default: false
>
> Because so many systems have been found to use underscores in the names
> they send in the SMTP HELO command, Exim by default permits them, though
> it is not in fact legal to use underscores in domain names.
>
> when, in fact, rfc2181, makes quite clear that there is no restriction on
> the characters used in domain names.
True, but rfc821 makes quite clear that there *are* restrictions on
those domain names used in SMTP (and these restrictions are stronger
than those in rfc822). I will attempt to improve the documentation.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
