Have you ever sent a message to the wrong recipient, included a wrong attachment? Have you ever sent a message to a colleague who's mobile device was lost or stolen?
You secure your devices by encrypting them or at the very least putting a PIN number on them, but the majority of mobile device users don't have any protection on their devices, not even a pin code. Sounds crazy, but according to the survey fully 56% of mobile device users have absolutely no security on their devices. Your friend is exposed, but you are not, right? Wrong. You see, you did send a sensitive message, perhaps an important document or perhaps something that you wasn't so important, but you would rather keep it private.
What you need to do is revoke the message immediately. Go to your Sent folder, select the message and click the REVOKE icon. The message is immediately not accessible to any recipient. They will still see the message in their account, but they will see the revoke icon and they will not be able to access it.
Consider setting message expiry options. This can be done at the time you send the message or even after. The only requirement is that you still have a copy of the message.
Limitation: feature not applicable to plain text messages.
Always encrypt your email. Take the decision to secure or not to secure out of the process.