Unfortunately, it is not possible to recall messages from a BlackBerry® device.
The BlackBerry service forwards the message to your BlackBerry from the Exchange server. The copy you get on your BlackBerry does not exist on the Exchange server. Therefore, the Exchange server is unable to manage that copy of the message. Since recalling is a service of the Exchange server, it is impossible to recall messages that have been forwarded to a BlackBerry.
BlackBerry is a registered trademark of Research In Motion Limited.