OME

Office 365 Message Encryption (OME) is Microsoft's email encryption service for sending protected messages and attachments to internal and external recipients. Internal recipients see the message decrypted automatically in Outlook; external recipients receive a notification email with a link to a secure web portal, where they authenticate (Microsoft, Google, or one-time passcode) and read the message. Senders apply OME by clicking the Protect button in Outlook or applying an encryption-enabled sensitivity label. Admins can also automate OME via Exchange transport rules. Included with Microsoft 365 E3, E5, Business Premium, Microsoft 365 Apps for Enterprise, and Office 365 E3/E5. Supports custom branding for the recipient portal.