Can someone help me with a mail merge?

[Arthur Botting]

I am trying to do a direct mail campaign myself. I have a Macintosh computer that is running Office 2008. When I open my data source in Excel I get a an error message that says "This file needs to be opened by the Excel Workbook text converter, which may pose a security risk if the file you are opening is a malicious file. Choose OK to open this file only if you are sure it is from a trusted source."

I choose OK because I have created the Excel file myself but I get an error message that says"The converter necessary to open this file cannot be found."

Has anyone else had this problem? I have searched the internet and not found anything that works to fix the Excel workbook text converter problem.

Can anyone on Bigger Pockets help me?