3.5.4 How can I delete an Item application?
Pull back the Item from your Outbox window. However, if the Item has already been sent, you can pull it back only if it is still in the Inbox at the send destination. After pulling back the Item, delete it.
For details about pulling back Items, see 3.3.2 Pulling back sent Items. For details about deleting Items, see 3.3.5 Deleting Items.