Is she sending a Rich Text Format e-mail. That is the primary cause of
..dat issues. Change to HTML or Plain Text.
> My wife has a new iMac with Snow Leopeord. When she sends Microsoft Word
> attachments, some recepients using Outlook recieve them with the correct file
> extension (.doc or docx), and some receive them with a .dat extension. Is
> there a setting in Outlook to allow the correct extension to be be maintained?