How to Send Encrypted Emails in Outlook and Office 365

Sep 27, 2025
3 min read

Email is the most common way businesses share sensitive information — but it’s also one of the least secure if left unprotected. Employee records, contracts, invoices, and even medical forms often get sent by email, which makes encryption essential for keeping your data safe.

The good news is that Microsoft Outlook and Office 365 include built-in encryption tools that make securing your messages simple. At East Coast Cybersecurity, we help businesses in Vero Beach and across Florida protect their email communications as part of a layered security strategy.

Here’s how to send encrypted emails using Outlook and Office 365.

Why Encrypt Your Emails?

Encryption ensures that only the intended recipient can read your message. Even if the email is intercepted in transit, the contents remain unreadable without the decryption key.

Common reasons small businesses encrypt emails:

Sending employee or customer personal data
Sharing medical or financial records
Protecting sensitive contracts or proposals
Staying compliant with regulations like HIPAA or PCI-DSS

How to Send an Encrypted Email in Outlook (Classic Desktop App)

Open a New Email
- Open Outlook and click New Email.
Write Your Message
- Add the recipient’s address, subject line, and write your email as usual.
- Attach any necessary files.
Turn on Encryption
- Go to the Options tab at the top of the message.
- Click the Encrypt button (it looks like a padlock).
- A bar will appear at the top of your email confirming it’s encrypted.
Choose the Encryption Level
- Encrypt-Only – Only the recipient can open and read the email.
- Do Not Forward – Same as above, but also prevents forwarding, copying, or printing.
Send the Email
- Once encryption is enabled, click Send.

How to Send an Encrypted Email in Outlook on the Web (Office 365)

Sign in to Outlook on the Web
- Go to outlook.office.com and log in with your Microsoft 365 account.
Compose a New Message
- Click New message in the top left.
Encrypt Your Email
- Click the Encrypt button (padlock icon) at the top of the message window.
- Choose Encrypt or Do Not Forward.
Send the Email
- Complete your email and hit Send.

What the Recipient Will See

Recipients inside your organization can open the email directly in Outlook. External recipients (like clients or vendors) will receive a secure message link. After verifying their identity, they’ll be able to read and reply securely.

Important Note About Setup

Encryption isn’t always turned on by default. It may need to be configured in your Office 365 or Microsoft Exchange environment before you can begin sending encrypted emails.

👉 If you need help setting up email encryption for your business, reach out to East Coast Cybersecurity. We’ll configure your system so you can send and receive encrypted messages with ease.

Important Note About Outlook Versions

As of today, the “New Outlook” app and some web versions of Outlook may not support the same encryption features as the classic Outlook desktop client. Microsoft is actively working on improving the experience, but for now, we recommend using the classic Outlook app for full encryption options.

Secure Your Business Email

Sending encrypted emails is one step toward securing your business communications, but it’s not the whole picture. At East Coast Cybersecurity, we provide: