Content-Type: multipart/alternative;
        boundary="----=25532899_4522_4927_1140_664401643181"

This is a multi-part message in MIME format.
------=25532899_4522_4927_1140_664401643181
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

This message is in MIME format. Since your mail reader does not
understand =
this format, some or all of this message may not be legible.
------=25532899_4522_4927_1140_664401643181
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

No, my mail reader understands it perfectly. It’s your crappy mail
client that sends out multipart/alternative mails which don’t contain
alternatives. Fuckers.