How does email encryption work in Microsoft 365?
Email encryption in Microsoft 365 protects messages in transit and at rest by ensuring that only the intended recipient can read the content. The service uses standards such as S/MIME and Office 365 Message Encryption (OME) combined with authentication and policies to prevent unauthorized access, protect sensitive information, and support compliance with regulatory requirements.
Background and overview
Email is often a target for cyberattacks. Microsoft 365 offers encryption solutions that ensure messages remain confidential, even if they pass through external networks.
Office 365 Message Encryption (OME)
OME enables the encryption of emails directly in Microsoft 365, allowing the recipient to read the message through a secure portal with authentication.
S/MIME encryption
S/MIME uses digital certificates to encrypt and sign emails, ensuring both privacy and sender authenticity.
Automatic encryption policies
Administrators can create rules that automatically encrypt emails based on content, recipients or sensitivity level.
Digital signing
Digital signatures verify that the message really comes from the sender and that it has not been tampered with during transmission.
Protection against unauthorized access
Encryption ensures that only authorized recipients with proper authentication can read the message.
Compliance and reporting
Encrypted emails are logged and can be monitored to meet regulatory requirements, such as GDPR, and internal security policies.
Integration with other security services
Email encryption works with DLP, ATP and Microsoft Purview to provide comprehensive protection against data leaks and attacks.
Key aspects of email encryption
- OME: Encryption via Microsoft 365 with secure portal for recipients.
- S/MIME: Certificate-based encryption and digital signing.
- Automatic policies: Encryption based on content, recipient or sensitivity level.
- Digital signature: ensures the authenticity of the sender and the integrity of the message.
- Access control: Only authorized recipients can read the message.
- Integration: Works with DLP, ATP and Purview for comprehensive protection.
Related questions
What is Office 365 Message Encryption (OME)?
An encryption service that protects emails and requires authentication to read them.
How does S/MIME work in Microsoft 365?
S/MIME uses digital certificates to encrypt emails and verify the identity of the sender.
Can emails be encrypted automatically?
Yes, administrators can create policies that encrypt messages based on content or recipients.
How does digital signing ensure email security?
It verifies that the message is authentic and has not been modified during transmission.
Can encryption support GDPR compliance?
Yes, encryption protects personal data and enables compliance with data protection rules.
