On Fri, Aug 28, 2015 at 05:59:08PM +0200, Per olof Ljungmark wrote: > Yes, that helped with Thunderbird but not from Horde/IMP where it still > bounces the same way. > > The difference seems to be that IMP sends a > "Content-Transfer-Encoding: quoted-printable" > > and TB > "Content-Transfer-Encoding: 8bit" > > Could this be the cause?
Yes, if IMP sends data claimed to be quoted-printable, but contaning unencoded non-ASCII characters. You'll need to capture a sample message and find the violation. -- Viktor.