The new Encrypt button contains both encryption options (S/MIME and IRM). The Permissions button is replaced with the Encrypt button. This feature is available only to Microsoft 365 Subscribers for Windows desktop clients. With the new Office update, email encryption in Outlook got better. New Encrypt button and updates to email encryption Microsoft 365 Message Encryption (Information Rights Management) - To use Microsoft 365 Message Encryption, the sender must have Microsoft 365 Message Encryption, which is included in the Office 365 Enterprise E3 license. S/MIME encryption - To use S/MIME encryption, the sender and recipient must have a mail application that supports the S/MIME standard. Any recipient without the corresponding private key, however, sees indecipherable text.

Only the recipient who has the private key that matches the public key used to encrypt the message can decipher the message for reading. Encrypting an email message in Outlook means it's converted from readable plain text into scrambled cipher text. When you need to protect the privacy of an email message, encrypt it. Outlook for Microsoft 365 Outlook 2021 Outlook 2019 Outlook 2016 Outlook 2013 Outlook 2010 More.

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