--On 7 August 2009 14:55:13 -0700 "John W. Baxter" <jwblist3@???>
wrote:
>
> [Catching up]
> Unfortunately, having a Message-Id: header is still a SHOULD, even in RFC
> 5322. So one really ought not to reject based (only) on their lack. It
> would be very nice if I could. (And if running a server only for myself,
> I likely would, with provision for an exception list.)
>
Yes, but understand the meaning of SHOULD.
"SHOULD This word, or the adjective "RECOMMENDED", mean that there
may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course."
The implication of ignoring any RFC5321 recommendation is that your mail
may not get delivered. I think you can safely assume that people who really
want their mail delivered will include a message-id.
Valid reasons for not generating a message-id will look like: "My MTA is
going to do it before releasing the email to the Internet, and is better
placed to generate a globally unique message id".
--
Ian Eiloart
IT Services, University of Sussex
01273-873148 x3148
For new support requests, see
http://www.sussex.ac.uk/its/help/
