In Sent / All Documents, select the message that u want to recall. Observe above the message list & click the recall message button or select recall option by clicking the More button and then recall message. Remember if this button is not displayed, then ur IT dept / Sys Admin may be potentially disabled this feature. There r 3 ways to do the task like select recipients, if the message was sent to multiple people / recall the message even if has been read by the recipient / send a report back to the sender about the success of the recall from each recipient. This is a specially powerful feature of LT ver8, that allows also to set by the recipient can disallow other people from recalling messages sent to them. Again u remember this feature (disable / enable) depends on ur IT deptt / Sys Admin