I am using FireFox3, and I just sent an MS-Excel attachment to another user on the Zimbra system. But when they had received the attachment, there was a question mark on the xls attachment, why?
Possibly FireFox3 doesn't know how to handle xls files yet. If you are the sender, and your FireFox program doesn't know how handle xls files, it's possible the Zimbra server will send the xls attachment something other then an MS-excel file.
For Example, the xls attachment could be sent using the following mime info.
Content-Type: application/octet-stream; name=Budget.xls
If the xls file was sent using "octet-stream" for the application, good chance this is why there was a question mark on the attachment.
The correct mime info should be:
Content-Type: application/vnd.ms-excel; name=Budget.xls
There's no easy workaround, except for have someone send an xls file that doesn't have "octet-stream" in the headers. When you attempt to open the file, you should get an "Open with..." prompt, and open the file with the MS-Excel application.