How to Send Encrypted Emails in Microsoft Outlook on Windows with a Microsoft 365 Subscription
Honestly, trying to send encrypted emails in Outlook can feel like hunting for buried treasure at first. The interface isn’t always straightforward, especially if your setup is controlled by an organization. But once you get the hang of it, it’s not too bad—and knowing where to look can save a huge headache. If you’re on Windows and rocking a Microsoft 365 subscription, here’s what finally clicked for me when I was troubleshooting this late at night.
Starting a New Email in Outlook
First, I made sure Outlook was fully open because surprisingly, it’s easy to forget to open the app or get distracted and then wonder why options are missing. Once I had Outlook running, I clicked the New Email button—it’s usually at the top-left corner, or just use Ctrl + N when inside Outlook. That gives you a blank message window to start composing. Easy enough, right? Well, not quite. The real challenge is finding the encryption options.
Finding the Encryption Settings
This part honestly took me a while because the encryption toggle isn’t always where you’d expect. In the new message window, look for the Options tab in the ribbon toolbar. Sometimes, especially on my older ASUS or if your Outlook is in a simplified mode, it’s hidden behind a little menu icon (like three dots). If you don’t see it, check whether your ribbon is collapsed or if you’re in a reduced view. The icon you’re after is usually labeled as Encrypt or might be a padlock or shield symbol. Microsoft updates things pretty often, so it might look different depending on your version.
In some cases, I had to dig into File > Options or Trust Center to verify if encryption features are enabled. If the encrypt icon is missing entirely, it could be a policy restriction or a missing add-in. Sometimes, encryption options are greyed out or disabled—particularly if your organization has policies that restrict certain features. Depending on your environment, you might need to update Outlook, install specific features, or get permissions from your IT admin.
Selecting and Confirming Encryption
Once I finally found the Encrypt button, clicking it opened a dropdown or modal with options. You might see options like Encrypt, Encrypt-Only, or something labeled Permissions. Choose Encrypt. If your setup supports it, you might see Encrypt with S/MIME—which needs certificates—or Encrypt with Office 365. The goal is to mark the message as encrypted so that only someone with the right setup can read it.
After selecting the right option, a little message appears at the top of your email, like “This message will be encrypted”—which confirmed I was doing it right. Keep in mind, encryption depends on account settings. Sometimes, it’s grayed out or unavailable if your admin configured things differently. Also, if you’re trying to use S/MIME, you’ll need a valid certificate installed in your system, which you can find under File > Options > Trust Center > Trust Center Settings > Email Security. That’s where you import or generate certificates. For O365 message encryption, it’s more about policies matching on both ends.
Composing and Sending the Secure Email
With encryption turned on, just finish writing your email—subject, body, attachments. When done, click Send. If everything is set up properly, Outlook will handle the encryption automatically. You might be prompted to choose a certificate if using S/MIME. Otherwise, with Office 365, the message encrypts transparently, and the recipient’s email client needs to support encryption too. If they don’t, they won’t be able to open the message without some extra steps, which is a pain but kind of inevitable.
One thing I learned: make sure the recipient’s email setup supports message encryption. Otherwise, they’ll just see gobbledygook or errors. Also, if you’re using S/MIME, check your certificates are installed and configured in Trust Center > Email Security. You can generate self-signed certificates for test or get legit ones from a CA. Without that, S/MIME encryption isn’t going anywhere.
Some Final Tips and Troubleshooting
After cracking this open a few times, it became clearer that organizational policies can really mess with your options—sometimes the encrypt button is hidden, greyed out, or simply missing. If that’s the case, contacting your admin might be necessary. Also, note that not everyone can decrypt your message unless they also have the correct setup—meaning matching certificates or permissions. It’s not foolproof, but it’s better than sending sensitive stuff in plain text.
And if your Outlook UI looks different or the options are not where I described, don’t stress; just poke around the File or Trust Center menus. Sometimes, the encryption features are in unexpected places, especially after updates or if your IT has customized the interface.
In Summary
In the end, sending encrypted emails with Outlook on Windows and Microsoft 365 boils down to opening a new message (Ctrl + N), heading to Options, clicking the Encrypt icon, selecting the right encryption mode, and then composing and sending as usual. Yeah, it’s a few extra clicks, but totally doable once you find the toggle.
Hope this helps — it took me way too long to figure out all the UI quirks and policy restrictions. Double-check your account settings, verify your certificates if using S/MIME, and ask your IT if something doesn’t seem right. Anyway, hope this saves someone else a weekend or at least a few hours of scratching their head. Good luck!