If you've sent a Mailock message by mistake - perhaps to the wrong person, or with the wrong attachment - you are able to stop the recipient from opening the message. They will still receive a notification email but will be unable to read the contents of your secure message.

You do this with the revoke option in the Outlook Add-in.

1. Find the message in your sent items and open it:

Click on the 'Email was Secure' button at the top left Click on 'Show access details'

4. In the 'Message access details' screen, find the recipient you want to revoke access from and tick in the 'Revoked' box:

   

You can also restore access to your message by unticking the 'Revoked' box.

You can still revoke a message, even after it has been opened. The only exception is if an unencrypted copy of the messages has been saved by the recipient.

If your recipient answers the challenge question incorrectly 5 times your message will automatically be revoked and you will be notified. If you want to give them more attempts just untick the 'Revoked' box as above.