I have a user who is sending an Excel spreadsheet as an attachment to a user at another company via Outlook 98. Every time she sends the attachment (in .xls), the user receives it as a .dat. Another user in the department sends the attachment the same way (all preferences/options the same in Outlook 98) to the same recipient and the spreadsheet is received as .xls not .dat.
What is causing the attachment to change extentions for the one user and not the other?
