It seems that the very first time (right after installation) an attachment of unknown type is received, Mozilla asks the user to open it using some application or save it to disk. Say this is a spreadsheet, of any kind (.sxc .xls tested), so we tell Mozilla to open the attachment using the corresponding application (excel.exe or ooocalc.exe or even soffice.exe and their linux equivalents) by browsing to its executable. We may also uncheck the button "always ask for this file type", presuming that next time the corresponding executable will be called automatically on choosing "open", or double-clicking on the attachment. The file opens the first time, but when another message including another attachment of that same type (say .sxc for Open/StarOffice) arrives and the user tries to open it directly, it's impossible. The "Enter name of file to save to..." dialog box appears, with (remarkably) a default filetype of ".exe" ! This happens both in Linux and Win98. After that point, any attachment that should be handled by OpenOffice cannot be directly opened, but only saved to disk. The .exe suffix is again proposed by default. Replication of problem ====================== 1. Send yourself an attachment (example: test.xls) using Mozilla. 2a. Receive it and right-click the attachment and choose "open". 2b. Alternatively receive it and double-click it. 3. Choose the application to open it (example: /home/alex/OpenOffice/program/soffice) 4. The file is displayed correctly. 5. Close the file and create another file of same type (e.g. test2.xls) 6. Attach the file to a mail and send it to yourself. 7. Receive it and try to open it. 8. It should remember the application association, but it only allows you to save it to disk. 9. From now on it's impossible to open directly any incoming attachment - they all have to be saved to disk first. This bug has been verified both with RC2 (Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0rc2) Gecko/20020510) on Linux and RC3 on Win98. Tested applications / file extentions were: Open Office (both Windows and Linux) .doc .sxc .sxc .xls .sxd BUG DID NOT APPLY to .pdf document (tested on Linux) Nonetheless OpenOffice doesn't even get called by Mozilla, so I guess it's Mozilla's ball...

Ok, I did some further testing. The problem seems to lie in the interaction between Mozilla's "helper applications" and the OS's MIME types. There is a quick workaround (use Preferences -> helper applications and declare a new application to handle .xls files, for example), but manually messing with mime types is off-limits to simple users - that's how I see it anyway. So, the problem is really the following: In my setup, clients are using OpenOffice 1.0, which handles .xls and .doc filenames as well as its native .sxc and .sxw formats. For some reason (which seems to be the exact declaration of the mime type, irrespective of the correct declaration of the filename extention), Mozilla asks the user how to handle an .sxc or .sxw attachment, but DOES NOT ask for an .xls or .doc attachment. It automatically tries to save the attached files, appending a .exe suffix. For other file extentions (e.g. .eps for PostScript files), Mozilla correctly asks which application to use, or where to save the file. WORKAROUND: I've manually declared a catch-all helper application on every Mozilla installation, stating that any .xls and .doc file (of mime type apllication/xyzfoo) should be handled by the OpenOffice executable.

pdf works because you likely already have it defined in a mailcap or mimetypes file. Resolving as dup of bug 93173 *** This bug has been marked as a duplicate of 93173 ***

verified dupe