To send a secure email in Outlook, you generally need to encrypt your email. This requires obtaining and installing a digital certificate (S/MIME) or using Microsoft 365 Message Encryption if your subscription supports it. After setting up encryption, you compose a new email, click on the Options tab, select Encrypt, choose the appropriate encryption method, and then send the email.

Steps to Send Secure Email in Outlook:

1. Obtain a digital certificate (from a trusted provider like Comodo, DigiCert, or GlobalSign) or ensure your Microsoft 365 subscription supports Message Encryption.
2. Install and configure the digital certificate in Outlook via File > Options > Trust Center > Trust Center Settings > Email Security.
3. Compose a new email and in the Options tab, select Encrypt or apply permissions like Do Not Forward.
4. Send the email; it will be encrypted so only authorized recipients can read it.

Encryption Methods:

• S/MIME: Uses digital certificates to encrypt emails; recipients must also have certificates.
• Microsoft 365 Message Encryption: Works with or without recipient certificates, available with certain Microsoft 365 plans.

Additional Features:

• Digital signatures can be added for authentication.
• Permissions like Do Not Forward control how recipients can use the email content.

This process secures your email against unauthorized reading and ensures the integrity of your message.