There's a bug when you enable format=flowed in QP-encoded messages. With soft newlines this message: ------------------------------------------------------------ Subject: test Gcc: nnml+archive:misc-mail From: Jesper Harder --text follows this line-- 1234567890 1234567890 123456789 01234567890 0123456789 ælsdkfj æa sdlfkj α ------------------------------------------------------------ Gets encoded like this: ------------------------------------------------------------ MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable 1234567890 1234567890 123456789 01234567890 0123456789 =C3=A6lsdkfj =C3=A6a= sdlfkj =CE=B1 ------------------------------------------------------------ Note the "a= ", which is malformed QP. I think the problem is that `fill-flowed-encode' is applied *after* QP-encoding (which I don't think is the right order). Reversing that order seems to fix it¹. But maybe we shouldn't flow text at all unless the CTE is 8bit or 7bit? (because QP supports soft linebreaks without f=f). ¹