User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0) Gecko/20100101 Firefox/8.0 Build ID: 20111104165243 Steps to reproduce: I'm Postmaster for Cologne University. We run IMP/Horde 3.3 as webmail frontend. In the last few days we received a number of complaints from webmail users that their attachment didn't reach the people they sent them to. Today I found out that this is caused by attachments with UTF-8-encoded file names. TB 8 doesn't like the encoding IMP uses. TB 7 and lower show the attachments, TB 8 doesn't. Here's an example: ... Content-Type: multipart/mixed; boundary="=_2viv1w5qcbv2" Content-Transfer-Encoding: 7bit User-Agent: Dynamic Internet Messaging Program (DIMP) H3 (1.1.4) X-IMP-Origin: REDACTED This message is in MIME format. --=_2viv1w5qcbv2 Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable ... --=_2viv1w5qcbv2 Content-Type: application/octet-stream; name*="utf-8''PR_Neueintr_%C3%84nd_HumFak2012.xls" Content-Disposition: attachment; filename*="utf-8''PR_Neueintr_%C3%84nd_HumFak2012.xls" Content-Transfer-Encoding: base64 Actual results: The message initially appears with the attachment symbol in the message list of TB 8, but as soon as you select it, the symbol disappears. The message pane/windows shows no indication of the presence of an attachment. Expected results: The attachment should be visible. Again, this works with TB 7 and below. It's a new issue with TB 8.