A large part of postal services does not use Exchange, but if you do have an account of this type, for sending emails I use MS Outlook 2007/2010, follow these steps.
Select in the section "Mail" in the navigation pane, the folder "Sent". Next, open the desired letter. In the "Actions" tab the "Messages", click "Other actions". Next, select "Review messages" and select "Delete unread copies".
Then specify whether to replace a letter with a new one or it just needs to be removed. Confirm your choice.
In addition to the attempt to revoke the letters made by you, you can send a new email instead of the previous. For example, if you accidentally forgot to attach some kind of attachment, this feature will be very useful. You can replace the old letter with the new, with the proper attachment.
In this case, the procedure remains the same only after you select "Review messages" you will need to specify a different value, namely "Delete unread copies and replace with a new message".
Next, click on the "OK" button to persist changes. You can also add or remove any attachment/attachments. Before the changes took effect, click on the "Send"button.
If you use to send emails email service Gmail log in to your mailbox through any browser that you like. Go to a section called "Settings", then select "Laboratory". Answer Yes to the query about using experimental features from the Gmail service.
Activate the function "Undo send mail", then save changes. Now if you accidentally send an email, you will have the opportunity for a few seconds after sending it back.