Philip Guenther wrote:
Folding of long header lines (as described in [IMAIL] 2.2.3) is
removed prior to interpretation of the data. The folding syntax (the
CRLF that ends a line plus any leading whitespace at the beginning of
the next line that indicates folding) are interpreted as if they were
a single space.
<pause>
Hmmm, that last paragraph actually differs from RFC 2822, section 2.2.3,
which says:
Unfolding is accomplished by simply removing any CRLF
that is immediately followed by WSP.
I.e., the leading whitespace should *not* be treated as a single space
but rather be left as is. Unless I hear screams, I'm going to remove
the sentence that starts "The folding syntax..." as conflicting.
RFC 2822, section 3.2.3 also contains:
Runs of FWS, comment or CFWS that occur between lexical tokens in a
structured field header are semantically interpreted as a single
space character.