Bruce Lilly wrote:
extension/user-defined (unlike 822, 2822 does not officially
distinguish the two distinct types) fields must conform to
the unstructured field restrictions on syntax, and that would
include the restriction on whitespace-only header lines.
Where do you see this in 2822 ? I found...
| unstructured = *([FWS] utext) [FWS]
...and that allows a trailing FWS. It should be *WSP to avoid
a whitespace-only header line. The "MUST NOT" for CFWS isn't
good enough, <unstructured> has no CFWS.
Is the software adding the 'X-SPAM-STATUS' line wrong
Does the software claim conformance with RFC 2822? If so, yes.
I'm not convinced. But so far nobody supported a s/[FWS]/*WSP/
cleanup in USEFOR.