Hi I am one of the experts here on Just Answer.com The easiest way to open this file with Powerpoint 2003 is to download and install the compatability pack for Office programshttp://www.microsoft.com/download/en/details.aspx?displaylang=en&id=3 Once downloaded and installed your office 2003 powerpoint will be able to open the file. After you open it you may want to do a save as to save it as a powerpoint 2003 ppt.Thanks for using just answer.com
Please let me know if you have any other questions
After you downloaded the converted did you received any error messages during the install of it?
Also when you try and open the file do you receive any errors?
If you received no errors the next thing I would download and install would be the office updates from Microsoft http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=8
This link is for service pack 3 for office 2003 once this is installed try to open the potx again,
When you try and double click on the file?
Try opening powerpoint 2003
In powerpoint go file open and select the file
Powerpoint should then try and open the file
Can I ask how you view your email?
Through a web page like gmail or through an email client like Microsoft Outlook?