When a user of MS Office for Mac tries to send a MS Office Excel user a file ending with the .xls extension, the recipient get the following message when they try to open it:
"The file you are trying to open is in a different format than specified by the file extension. Verify the file is not corrupted and from a trusted source."
I tried having the user email the same file to me and got the error message, but when I chose "Open the file" it opened fine. Is there some conflict with MS Office for Mac and regular MS Office users? thanks if you can be of any help.