There seems to be a problem with the character encoding of attachment
filenames. with a name written in the MUA as Vertrag-für-Leistungen.doc
the MUA encodes the Umlaut "ü" correctly in quoted-printable as "=FC"
and attaches the encoding tag ISO-8859-1. For some reason our installed
sanitizer then removes the "ISO-8869-1" which results in the MUA to
The processing seems to be done in sub ParseContentHeader of
Anomy/MIMEStream.pm where our version is $Id: MIMEStream.pm,v 1.80.