If you're dbl-clicking the attachment icons in the email message, try saving
the file to your HD *first*, then run that file in PPt.
Otherwise, you need to provide more information, such as;
What version of Mac OS,
What version of PPt,
Source of the PPt files (Windows, Mac, version)
Anything more about content of the files.

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HTH |:>)
Bob Jones
[MVP] Office:Mac
>I don't use Office much, but whenever I receive an attachment that
> opens and plays with Powerpoint, it seems to freeze my machine. The
> item plays for a bit, then stops and I cannot close it, force quit it,
> shut down the machine, or anything. Can't even remember how I finally
> got it off! Any suggestions from anybody?? Many thanks.