How to Send Secure Email Messages in Outlook: The Ultimate Guide to Encrypt Email and Secure Your Communication

Email security is crucial for protecting sensitive business information and maintaining client trust. This blog provides a step-by-step guide to sending encrypted emails using Outlook’s built-in tools.

Dan Sharp

President & CEO

Imagine this: you’re about to send an email containing sensitive client data, a critical contract, or financial information. But as you hit "send," a lingering worry settles in—what if someone intercepts this message? What if your private email ends up in the wrong hands? For businesses relying on Microsoft Outlook, understanding how to secure email communications isn’t just a technical necessity—it’s a safeguard for your reputation, trust, and peace of mind.

In this guide, you’ll discover how to send a secure email in Outlook, ensuring your messages stay private and protected.

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how to send a secure email in outlook

Why email security matters more than ever

Did you know that 94% of malware is delivered via email? This makes email the number one attack vector for cybercriminals looking to exploit vulnerabilities. Protecting your email isn’t just about avoiding breaches—it’s about shielding your business from costly downtime, compliance issues, and damaged trust.

By sending sensitive information with encryption, you transform your email into an unreadable code that only the intended recipient can unlock. For Microsoft users, the tools to encrypt emails are already at your fingertips. Let’s explore how you can leverage them.

What is email encryption?

Before we dive into the "how-to," let’s clarify the "what." Email encryption is the process of scrambling the contents of your messages so only the intended recipient can read them. Think of it as locking a letter in a tamper-proof envelope that only the recipient’s key can open.

Encryption in Outlook goes further by safeguarding contents and attachments, ensuring that even if someone intercepts the email, they can’t access its information. With tools like Microsoft Purview Message Encryption, this process becomes seamless, protecting your messages in a few easy steps.

How to send a secure email in Outlook

Sending an encrypted email in Outlook is simpler than you might think. Follow these steps to protect your email messages in Outlook for Windows or the web:

1. Enable encryption in Outlook

  • Open your email in Outlook.
  • In the menu bar, select “Options.”
  • Choose Encryption Options from the dropdown menu.
  • Select the encryption level: "Encrypt-Only" or "Do Not Forward."

2. Compose your email

  • Click “New Message” to open the email composer.
  • Add your recipient’s email address and write your message. Attach any necessary files.

3. Apply encryption

  • Before sending, click “Options” > Permissions.
  • Choose 365 Message Encryption to encrypt the email and protect any attachments.

4. Send your encrypted email

  • Hit "Send." Your email is now secured, ensuring only the intended recipient can access it.

Pro Tip: Using Microsoft 365? This process is even smoother when you’re a Microsoft 365 subscriber, as encryption features are integrated into your Outlook account.

Send your encrypted email

Viewing and replying to encrypted messages

When you send an encrypted email, the recipient will receive a notification letting them know that a secure message is waiting for them. This notification includes clear instructions on how to access the encrypted email. To ensure maximum security, the recipient will need to sign in using either their Microsoft account credentials or a one-time passcode sent directly to them. 

This extra step verifies their identity, keeping the email and its contents protected from unauthorized access. Once verified, the recipient can easily view the message and even reply securely, maintaining the encrypted communication chain to protect sensitive information.

Key benefits of sending secure emails

Email remains a primary tool for business communication—and a significant target for cyberattacks. From sensitive financial details to personal customer information, the data shared over email needs robust protection. By leveraging email encryption, you not only protect your business but also build trust and comply with essential regulations. Here are the key benefits of sending secure emails:

1. Compliance with regulations

Regulatory frameworks like GDPR, HIPAA, and others mandate that businesses safeguard sensitive information. Encrypting your emails in platforms like Outlook ensures compliance, reducing the risk of non-compliance penalties and legal complications.

2. Prevent unauthorized access

Cybercriminals are continually evolving their tactics, making data security a top priority. Email encryption acts as a digital lock, ensuring only authorized recipients can access the content and protecting your communications from breaches and unauthorized interception.

3. Preserve customer trust

Your customers entrust you with their most sensitive information. By encrypting emails, you demonstrate your commitment to keeping their data secure. This not only reassures your customers but also enhances your credibility and fosters long-term relationships built on trust.

The tools you’ll need: Microsoft 365 Message Encryption

Microsoft's powerful Microsoft 365 Message Encryption tool makes securing your emails easier than ever. This built-in feature ensures that sensitive communications remain private and protected, no matter who you’re emailing.

Whether you’re on an Office 365 Enterprise E3 plan or a more standard Microsoft 365 subscription, the encryption tools are designed to seamlessly integrate into your workflow. With just a few clicks, you can protect your emails, ensuring they are accessible only to the intended recipient.

From safeguarding confidential business deals to securing personal client information, Microsoft 365 Message Encryption equips you with the robust tools needed to confidently handle sensitive communications while maintaining compliance with industry regulations.

A step-by-step walkthrough for sending encrypted messages with Microsoft 365

Microsoft 365 makes it simple to secure your communications with its robust encryption features. Whether you’re sharing sensitive information or safeguarding confidential messages, these tools ensure your data stays protected. Follow this step-by-step guide to send encrypted messages directly within the Microsoft 365 environment:

  1. Open Outlook on the web or desktop app.
  2. Select New Message from your Inbox.
  3. In the pane, click "..." to expand the menu.
  4. Choose “Encrypt” and then select Encrypt-Only for maximum flexibility.
  5. Send the email to the recipient.

Your recipient’s email provider will manage the decryption process, ensuring a seamless experience.

Overcoming common encryption challenges

Some users worry about the technical complexity of encryption or whether it will work seamlessly with non-Microsoft email providers. Fortunately, Outlook’s encryption protocols are designed to support a variety of email accounts, making secure communication accessible to everyone.

So, what happens if your recipient uses Gmail or another third-party email service? Don’t worry! They’ll still be able to access your encrypted message. When they receive your email, they’ll be prompted to follow a secure link that directs them to a Microsoft portal. 

There, they can verify their identity using a one-time passcode or by signing in with a Microsoft account. Once verified, they can view and even reply to the encrypted message securely—ensuring sensitive information stays protected, no matter what email provider they use.

Take the next step to secure your inbox

Your emails are more than just words on a screen—they’re contracts, confidential plans, and promises to your clients. By learning how to send a secure email in Outlook, you’ve already taken the first step toward safeguarding your business.

But you don’t have to do it alone. At Infoware, our experts specialize in streamlining IT security, making email encryption effortless.

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Take the next step to secure your inbox

Frequently asked questions

What is the process for sending encrypted emails in Outlook?

To send encrypted emails in Outlook, compose a new message, go to the Options tab, and select the 'Encrypt' option. Make sure you have an Office 365 account that supports encryption, such as Azure Information Protection Plan 1. This will help secure your email and protect sensitive information.

Can I use the new Outlook to encrypt my messages?

Yes, the new Outlook supports message encryption. When composing a message, you can use the encryption option in the Options tab to ensure that your email is protected.

What happens if the recipient cannot read the encrypted message in Outlook?

If the recipient cannot read the encrypted message, they will receive instructions on how to access the message. They may need to use a Microsoft account to read the message or follow the steps provided in the transcript sent along with the email.

Is it necessary for both sender and recipient to have an Office 365 account to use message encryption?

Yes, both the sender and recipient must have compatible Office 365 accounts for the encryption options to work seamlessly. This ensures that both parties can send and read encrypted emails securely.

How can I ensure that my email messages are encrypted using TLS?

To ensure that your email messages are encrypted using TLS (Transport Layer Security), you should check that your email server settings are configured to use TLS. If you're using a corporate 365 email account, your IT department typically manages this.

What are some additional email security measures I can take besides encryption?

Besides encryption, you can implement multi-factor authentication, regularly update passwords, and use rights management features available in Microsoft Office to secure your emails further. These measures help protect your 365 email account from unauthorized access.

Where can I find more information that would be helpful for encrypting messages in Outlook?

For more information on how to encrypt messages in Outlook, you can visit the Microsoft Support website. They have comprehensive guides and resources on office message encryption and how to use the encryption option effectively.

How can I provide feedback on the email encryption feature in Outlook?

You can give feedback on Outlook's email encryption feature by navigating to the Help section and selecting 'Feedback.' Your insights are valuable for improving the email encryption options and overall user experience.

What is the expiration period for encrypted messages sent through Outlook?

The expiration period for encrypted messages can vary based on the settings applied by the sender. When sending an encrypted message, the sender can set expiration dates to control how long the recipient can access the message.