To recall a sent e-mail
Both parties have to be on Microsoft Exchange Server
You need to be running Outlook XP or later
If email recipient has already read the message, the email cannot be recalled
To recall a sent email do the following:
In Outlook Navigation Pane (far left, has all your folders) select your Sent Items folder
Find the email you wish to recall, double click on the email
Under Actions select "Recall this Message..."
Select which properties you wish to do and click OK
Note: Doesn't always work but worth a try if you sent an email by mistake or sent an email in haste
Remember to select "Tell me if email message recall succeeds or fails" for each recipient.