When you click the Read Mail button in the Command Bar in Internet Explorer 7, the mail client may not open.
This happens if the default mail client is not correctly set. Follow these steps to resolve the problem.
You can set the default email program in the Internet Options dialog box. Open Internet Explorer, click the Tools menu, choose Internet Options. Click Programs tab and select your mail client from the drop-down list. Click OK and close the dialog.
Note that you need to login as Administrator or equivalent to perform the above steps, as this is a system-wide setting.