That is not correct MIME, it should be
Content-Type: multipart/related; start="op.mhtml.1238180415787.b2f4904f395b37a5@192.168.0.195"; boundary=----------ghanZ9pgiqEYDh7aC9oLbg
'<', '>' and '@' are tspecials, and the standard says
; Must be in quoted-string, ; to use within parameter values
about tspecials.