Email is one of the fastest ways to share information, but it is also one of the easiest ways for that information to be exposed. Whether you’re sending a contract, medical record, or confidential client file, encrypting your professional email keeps your message private and your recipient protected.
Outlook includes built-in encryption features that help you send secure messages directly from your inbox. In this guide, you’ll learn how to send an encrypted email in Outlook, including the desktop, web, and mobile versions. You’’ll also learn about encryption types, how recipients can read encrypted messages, and what to do if something goes wrong.
Why people encrypt emails in Outlook
Email encryption scrambles your message into unreadable code while it travels from sender to recipient. Only the intended recipient has the key to unlock and read it. This protects sensitive data from hackers, phishing attempts, or accidental sharing.
According to Huntress, 1 in 3 data breaches involve “shadow data”, which is information created or stored without an organization’s knowledge, such as employees saving work emails to personal accounts or duplicating sensitive files. Because this data often goes untracked, IT teams cannot protect or recover it during a breach. Encrypting emails in Outlook helps reduce this hidden risk by keeping every message securely contained within your organization’s systems.
Not only that, but a Verizon report found that emails were compromised in 61% of data breaches in 2025. So encrypting your emails could be the additional security measure that keeps your business protected.
Microsoft Outlook supports two main encryption systems for security-conscious users:
- Microsoft 365 Message Encryption (OME): Allows secure messaging without needing certificates.
- S/MIME encryption: Uses digital certificates on both the sender and recipient sides to verify identity and protect content.
Both methods help protect privacy and meet compliance standards such as GDPR and HIPAA.
Related: How to recall an email in Outlook
How to send encrypted emails in Outlook (desktop)
If you use the Outlook desktop app, encrypting an email is quick once your Microsoft 365 account is active.
- Open a new email Go to Home > New Email or use the keyboard shortcut
Ctrl + N. - Select the Options tab You will find encryption settings under this menu.
- Click Encrypt If the button is hidden, click Permissions > Encrypt Message Contents and Attachments.
- Choose your encryption type Encrypt-Only lets recipients read but not remove encryption. Do Not Forward prevents forwarding, printing, or copying.
- Compose and send your email A small lock icon will appear beside the subject line confirming encryption is on.
A note on compatibility: Encrypted messages work best when both sender and recipient use Outlook or Microsoft 365 accounts. If you send an encrypted email to a Gmail or Yahoo user, they will receive a secure link to view the message in a protected Microsoft portal.
How to send encrypted emails in Outlook (mobile web)
If you prefer Outlook on the web or use Outlook.com, you can still send encrypted messages without installing any software.
- Go to Outlook.com and click New Message.
- In the message window, click the Encrypt icon (padlock).
- Choose your protection level:
- Encrypt: The message is encrypted, but recipients can forward it.
- Encrypt & Prevent Forwarding: The message is locked to prevent forwarding, printing, or copying.
- Write your message and select Send.
Free Outlook.com users can encrypt messages, but advanced permissions such as Do Not Forward are exclusive to Microsoft 365 subscribers.
Recipients using Gmail or other mail providers will receive a link to the Microsoft 365 Message Encryption portal, where they can verify their identity through a one-time passcode before viewing your message securely.
This method makes it easy to send a secure email in Outlook from any browser.
How to send encrypted emails in Outlook (mobile app)
Outlook’s mobile app supports encryption for Microsoft 365 accounts, making it simple to protect sensitive emails while working remotely.
- Open the Outlook app and tap the Compose icon.
- Tap the three dots (•••) in the top-right corner.
- Select Encrypt and choose Encrypt-Only or Do Not Forward.
- Write your email and tap Send.
Encryption in the Outlook mobile app is only available for Microsoft 365 and Exchange accounts. If you use IMAP, POP, or a free Outlook.com account, the encryption option will not appear.
Attachments follow the same rules as the message: when forwarding is disabled, recipients cannot share or download them. Before you hit send, check for the small padlock icon at the top of your message to confirm encryption is active.
Comparing your encryption options in Outlook
Outlook offers three main ways to protect your messages, depending on how tightly you want to control access.
Encrypt-Only protects your email so only the intended recipient can open it. They can still forward or copy the message, but the encryption remains in place. It’s a good option for sharing sensitive information with trusted contacts.
Do Not Forward adds another layer of security. It encrypts your email and blocks forwarding, copying, and printing entirely. This option is best for internal communication or confidential documents that should stay private.
S/MIME encryption goes a step further by using digital certificates on both the sender’s and recipient’s devices to verify identity and encrypt the message. It’s most often used by organizations that need to meet compliance or regulatory standards.
More on Outlook: How to block an email in Outlook
How to read encrypted emails in Outlook
When you receive an encrypted email, Outlook automatically recognizes and decrypts it if your account supports encryption.
For Outlook desktop or Outlook.com users:
- The email opens normally with a lock symbol beside the subject line.
- If forwarding is restricted, you will see a banner stating that actions like copying or printing are disabled.
For Gmail, Yahoo, or other email users:
- You will receive an email notification with the subject “You’ve received an encrypted message.”
- Click Read the message to open Microsoft’s secure portal.
- Sign in with a Microsoft account or request a one-time passcode.
Troubleshooting if encrypting doesn’t work
Sometimes Outlook encryption runs into small glitches, especially if you are switching between accounts or browsers. Most issues are quick to fix once you know where to look. Try these steps:
- Clear your browser cache and cookies: Old data can interfere with secure portals or message loading.
- Switch browsers: Outlook’s encryption portal works best on Chrome, Edge, or Firefox.
- Sign out and back in: A fresh login can reset permission errors tied to your Microsoft 365 session.
- Check your account type: Encryption options only appear for Microsoft 365 and Exchange accounts, not IMAP or POP.
- Disable browser extensions temporarily: Privacy or ad-blocking tools can sometimes block Microsoft’s encryption scripts.
- Ask your IT admin to review settings: In enterprise setups, administrators can enable or adjust automatic decryption within Microsoft Purview compliance policies.
Enhancing your email security with Fyxer
When your inbox contains confidential conversations, data security matters as much as productivity. Fyxer is built with the same level of protection used by global enterprises, giving teams a secure way to automate email without ever compromising privacy.
Fyxer never uses your data to train third-party AI models such as OpenAI. Everything that happens in your inbox stays within your control. Drafts are created, not sent, and meeting insights are captured only when participants give consent.
Our security framework is designed for organizations that expect enterprise-grade protection.
- Full compliance: Fyxer meets SOC 2 Type II, ISO 27001, HIPAA, and GDPR standards.
- Continuous monitoring: We use Google’s Security Command Center and perform regular penetration testing to stay ahead of potential risks.
- Strict access control: Our engineers operate under the Principle of Least Privilege, with temporary read-only access granted only when necessary.
Fyxer keeps sensitive data encrypted, monitored, and compliant across every workflow, from inbox organization to meeting summaries. This ensures that your private information always stays private.
Encrypting emails in Outlook FAQs
Can I encrypt emails without Microsoft 365?
Yes. You can use S/MIME encryption, which requires both you and your recipient to have installed digital certificates. However, Microsoft 365 Message Encryption (OME) features such as “Encrypt-Only” and “Do Not Forward” are exclusive to Microsoft 365 accounts.
How do I know if my email was encrypted?
You can confirm your message was encrypted before or after sending it.
- Before sending: Look for the padlock icon in the compose window.
- After sending: Check your Sent folder. A small lock will appear beside the message subject line. Hover over it to view the encryption type.
- On web: You will see a confirmation banner at the top of your email reading “This message is encrypted.”
If the lock does not appear, your account may not include encryption permissions. Contact your IT administrator or confirm that you are using a Microsoft 365 plan that supports OME.
Can Gmail or Yahoo users open encrypted Outlook emails?
Yes. They receive a secure link to Microsoft’s encrypted message portal. After verifying their identity through a one-time passcode or Microsoft login, they can read your message securely in a web browser.
Is encryption available in Outlook mobile?
Yes, but only for Microsoft 365 and Exchange accounts. If you are using a free Outlook.com, Gmail, or IMAP account, the encryption option will not appear in your app.
What’s the difference between Encrypt-Only and Do Not Forward?
Encrypt-Only protects message content during delivery but allows forwarding. Do Not Forward adds extra protection by blocking forwarding, copying, and printing.
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