Office 365 Message EncryptionEncryption is the process by which data is made illegible and unusable for unauthorized viewers. In order to use or read encrypted data, you must decrypted will. A secret key is required for this. There are two types of top-level encryption: symmetrical and asymmetrical . In the symmetric encryption the same key is used to encrypt and decrypt the data.... (OME) is a service built on top of Azure Rights Management (Azure RMSAzure Rights Management (Azure RMS) is the cloud-based protection technology from Azure Information Protection. Activation in the admin center Image source: https://channel9.msdn.com/Series/Information-Protection/Azure-RMS-user-experience) that allows you to send encrypted emails to people inside or outside your organization, regardless of the email address. Destination address (Gmail, Yahoo! Mail, Outlook.com, etc.). As an administrator, you can set up transport rules that define the conditions for encryption. When a user sends a message that matches a rule, encryption is automatically applied. To view encrypted messages, recipients can get a one-time identifier, sign in with a Microsoft account, or sign in with a work, school, or college account associated with Office 365. Recipients can also send encrypted replies. You don’t need a Microsoft 365 subscription to view encrypted messages or send encrypted replies.