Outlook Recalling An Email

NOTE #1: These directions only work if you and the receiver are on same Microsoft Exchange server and the receiver has not yet marked the email as read.

Outlook 2013:

http://office.microsoft.com/en-us/outlook-help/recall-or-replace-an-email-message-after-it-is-sent-HA102749462.aspx

Outlook 2010:

http://office.microsoft.com/en-us/outlook-help/recall-or-replace-an-email-message-that-you-sent-HA010354931.aspx