Re: Syntax validation of articles by injecting agents

[Russ Allbery <rra@xxxxxxxxxxxx>]

"Charles Lindsey" <chl@xxxxxxxxxxxxxxxx> writes:

> Eh? How does it imply that? If there are no Content-* headers, then
> there is no requirement for MIME-Version.

See Julien's post:

| NN for instance does not generate MIME-Version: header fields
| although "user agents MUST meet the definition of MIME conformance"
| ("a mail user agent that is MIME-conformant MUST always generate
| a "MIME-Version: 1.0" header field in any message it creates").
| I believe this sentence applies to news user agents too, otherwise
| a reference to MIME is useless.

The first quoted statement is from RFC 5536 section 2.3, with an
accompanying reference to RFC 2049.  The second quoted statement is from
RFC 2049 section 2.

Now that I think about it, though, this only places a requirement on the
user agent.  It doesn't require that the server reject the message, so I
think the original problem isn't actually that significant of a problem.
MIME-compliant agents, such as injecting agents, are allowed to accept
non-MIME messages.

> But aren't injecting agents allowed to remove a Path header that is
> received?

See point 2 in Duties of an Injecting Agent in RFC 5537, which requires a
syntax check on the Path header.

> For sure, many of them routinely do. In any case, fixing (or removing) a
> broken header is always a way out of the problem.

Injecting agents are specifically discouraged (SHOULD NOT) from fixing or
remove any header fieldss other than Path.

-- 
Russ Allbery (rra@xxxxxxxxxxxx)             <http://www.eyrie.org/~eagle/>