Email is one of the most widely used communication tools in business—but also one of the most targeted by cybercriminals. Sensitive business data, financial records, and client information often travel through email, making it a prime target for interception. This is why email encryption has become essential for professionals across industries.
If you’ve ever received a secure message and wondered how to view encrypted email in Outlook, you’re not alone. Many users find the process confusing, especially when different encryption methods are involved. In this guide, we’ll explain what encrypted email is, why it matters, and provide step-by-step instructions to view encrypted messages in Outlook on desktop, web, and mobile.
What is an Encrypted Email in Outlook?
An encrypted email is one that has been scrambled into unreadable text to prevent unauthorized access. Only the intended recipient with the correct credentials or decryption key can read the message.
Encryption Methods in Outlook
-
S/MIME (Secure/Multipurpose Internet Mail Extensions): Uses certificates to encrypt messages. Common in corporate settings.
-
Microsoft 365 Message Encryption (OME): A cloud-based service that allows users to send and read encrypted emails without manually installing certificates.
In simple terms: encryption ensures that your email content is secure, private, and tamper-proof.
Why Email Encryption Matters
-
Protecting Confidential Data: Sensitive information like financial records, contracts, or healthcare data remains secure.
-
Regulatory Compliance: Industries like healthcare (HIPAA) and finance must comply with strict data protection laws.
-
Defense Against Cyber Threats: Encrypted emails reduce the risk of phishing, spoofing, and unauthorized access.
Fact: According to Microsoft, nearly 94% of targeted malware is delivered via email, making encryption a critical safeguard.
How to View Encrypted Email in Outlook
Viewing in Outlook Desktop App (Microsoft 365 / Office)
-
Open the encrypted email in the Outlook desktop app.
-
If prompted, sign in with your Microsoft 365 account or use your S/MIME certificate.
-
Outlook will automatically decrypt the message if you have the right credentials.
-
Attachments will also be decrypted and can be opened normally.
Tip: If your organization uses S/MIME, make sure your digital certificate is installed on your system.
Viewing in Outlook Web (OWA – Outlook on the Web)
-
Log in to Outlook on the Web via your browser.
-
Locate and open the encrypted email.
-
If OME is used, click Read the message → Sign in with your Microsoft account or a one-time passcode.
-
Once authenticated, Outlook will display the decrypted message.
-
Download secure attachments directly from the web interface.
Viewing in Outlook Mobile App (iOS & Android)
-
Open the Outlook app on your phone.
-
Find the encrypted message and tap Read the message.
-
Log in with your Microsoft account or organizational credentials.
-
The email and attachments will decrypt automatically.
Note: Some encrypted messages require the Microsoft “Message Viewer” app if you’re an external recipient.
Troubleshooting Issues with Encrypted Emails
Even with proper steps, users may face difficulties. Here are common issues and solutions:
-
Can’t Open Encrypted Email: You may be using the wrong account or missing a digital certificate.
-
Error Message – “You can’t open this message because it’s encrypted”: Install the correct S/MIME certificate or log in with the right credentials.
-
Attachments Won’t Open: Make sure you’re viewing in a supported version of Outlook. Some older versions may not fully support OME.
-
External Users (Non-Microsoft Accounts): Use the one-time passcode option or download Microsoft’s “Message Viewer” app.
Best Practices for Managing Encrypted Emails
-
Keep Certificates Updated: Expired certificates can block access to encrypted messages.
-
Train Employees: Ensure all staff know how to identify and open encrypted emails.
-
Enable MFA (Multi-Factor Authentication): Adds an extra security layer beyond passwords.
-
Backup Your Mailbox: Regular backups protect against accidental loss or corruption.
-
Use Updated Outlook Versions: Always update Office apps to ensure encryption compatibility.
Conclusion
Encrypted email is one of the strongest defenses against modern cyber threats. By knowing how to view encrypted email in Outlook, professionals can ensure secure communication while staying compliant with regulations.
Outlook makes it relatively straightforward—whether on desktop, web, or mobile—provided the right credentials or certificates are in place.
Call to Action: Don’t wait until a sensitive email goes unread. Make sure your Outlook app and certificates are updated, and train your team to handle encrypted messages confidently.
FAQs on How to View Encrypted Email in Outlook
1. Can I view encrypted emails in Outlook without a certificate?
Yes, if the sender uses Microsoft 365 Message Encryption, you can log in with your account or a one-time passcode.
2. How do I know if an Outlook email is encrypted?
Encrypted messages often display a lock icon or include instructions like “Read the message.”
3. Why can’t I open an encrypted email in Outlook?
You may be signed in with the wrong account or missing a required certificate.
4. Can Outlook Mobile open encrypted emails?
Yes, the Outlook app supports encrypted messages, but some may require Microsoft’s “Message Viewer.”
5. Do I need Microsoft 365 to view encrypted emails?
Not always. External users can use a one-time passcode option to access encrypted messages.
6. What’s the difference between S/MIME and OME in Outlook?
S/MIME relies on certificates, while OME uses Microsoft cloud-based encryption.
7. Can I forward encrypted emails in Outlook?
Yes, but forwarded emails may remain encrypted, requiring the recipient to authenticate again.
8. Are encrypted emails completely secure?
While encryption greatly improves security, no system is 100% foolproof. Strong passwords and MFA are still essential.