On Tue, 20 Jul 1999, Foster, C. wrote:
> It would appear that exim does not
> canonicalize domains in addresses when it finds a CNAME.
> Is this true? If so, why is it so, when RFC 1123 states:
>
> 5.2.2 Canonicalization: RFC-821 Section 3.1
>
> The domain names that a Sender-SMTP sends in MAIL and RCPT
> commands MUST have been "canonicalized," i.e., they must be
> fully-qualified principal names or domain literals, not
> nicknames or domain abbreviations. A canonicalized name either
> identifies a host directly or is an MX name; it cannot be a
> CNAME.
>
> I'm not saying that I think exim *should* do this - I don't
> see a good reason for messing about with recipient addresses.
I think (a) I'd overlooked that and anyway (b) I agree with you. I don't
see a good reason for messing about. I do agree that people should not
set up their DNS to use CNAMES for mail; MX records provide the
indirection facility, and CNAMES just make more lookup work. However, if
a CNAME is encountered, it seems reasonable to do something sensible
with it.
Exim will canonicalize nicknames.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.