Some emails carry information you don't want living forever in someone else's forwarded thread — a document, a personal detail, something time-sensitive.
Gmail has a built-in mode for exactly that, and it's easy to miss because the button is small and unlabeled.
Here's the trick:
The lock-and-clock icon in the compose window turns on Confidential Mode, letting you set an expiration date and, optionally, require an SMS passcode to open it.
How to use it
- Start a new message.
- In the bottom toolbar of the compose window, click the lock-and-clock icon.
- Set an expiration period — from 1 day up to 5 years.
- Optionally require an SMS passcode for non-Gmail recipients.
- Click Save, then send as usual.
Where it helps most
Sending something sensitive without leaving a permanent, forwardable copy sitting in someone's inbox indefinitely.
One thing to watch for
Confidential Mode restricts Gmail's own forward, copy, print, and download options — it doesn't stop a recipient from taking a screenshot. Treat it as a deterrent, not a guarantee.
Found a faster way to do this, or noticed it works differently on mobile? That’s what the comments are for — this section connects to your comment system of choice (Disqus, giscus, etc.) once the site is live.