MP> "Patches Welcome"

All you have to do is (using your much greater knowledge of the
program) is to add a paragraph to complement

The 'raw body' of a message is the raw data inside all textual
parts. The text will be decoded from base64 or quoted-printable
encoding, but HTML tags and line breaks will still be present.
The pattern will be applied line-by-line.

and

The full message is the pristine message headers plus the pristine
message body, including all MIME data such as images, other attach-
ments, MIME boundaries, etc.

but concerning the headers.

Also mention the differences between pcregrep and spamassassin
expressions, i.e., just how many \escape items on man perlre are
allowed or not. All we know is \d and \S are OK, as there is an
example on the page.
header FROM_HAS_MIXED_NUMS From =~ /\d+[a-z]+\d+\S*@/i
But some of the others I tried gave big warnings.