User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.2.16) Gecko/20110319 Firefox/3.6.16 ( .NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.1.16) Gecko/20101125 Thunderbird/3.0.11 Thunderbird does not display 3'd multipart/alternative The MS Outlook 2010 creates Calendar invitations with 3(!) MIME multipart/alternative: - Content-Type: text/plain - Content-Type: text/html - Content-Type: text/calendar The text/plain contains an empty body, text/html contains a white html and text/calendar contains *NAMELESS* base-64-encoded content (actually .ics file ) Technically, it's not attachment, it's just a multipart/alternative branch. The MS Outlook Express shows such message with "attachment". Reproducible: Always Steps to Reproduce: 1. Create a multi-branch multipart/alternative message (one branch should be text/calendar) 2. Try to open it in the Thunderbird 3. Actual Results: Blank screen. Seems Thunderbird selects text/html branch There is no text/calendar part at all Expected Results: text/calendar should be converted into something like ATT000.isc where file name is arbitrary selected and extension is a system-wide extension for MIME type text/calendar

similar bugs bug 538043 bug 553362 bug 574989 bug 621665 bug 632961 bug 636253

I've just upgraded to Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.2.15) Gecko/20110303 Thunderbird/3.1.9 The same result.