Content-Type: text/plain Content-Disposition: inline Content-Transfer-Encoding: binary MIME-Version: 1.0 X-Mailer: MIME-tools 5.411 (Entity 5.404) RT-Send-CC: X-RT-Original-Encoding: iso-8859-1 Content-Length: 117 Looks like I missed a test case, the patch I checked in based on the one in the ticket doesn't fully fix the problem.