Send S/MIME or Microsoft Purview encrypted emails in Outlook using a work or school account with a qualified Microsoft 365 subscription.

Learn how to use encryption and other security settings to protect messages sent from Outlook.

If you have a Microsoft 365 Family or Microsoft 365 Personal subscription, Outlook includes encryption features that let you share your confidential and personal information while …

You can use encryption and digital signatures in new Outlook, classic Outlook, and Outlook on the web for work or school accounts to increase the security of messages.

Learn how to identify and open encrypted and protected emails no matter what email client you're using.

Learn how to use digital signatures and encryption in Outlook for Mac. Both the sender and recipient must have a mail application that supports the S/MIME standard.

Under Microsoft Outlook Trust Center, select Trust Center Settings. On the Email Security tab, under Encrypted Mail, select the Add digital signature to outgoing messages check box.

To turn S/MIME on: In Outlook, tap the Account control at the top left, then select the Settings button near the bottom left. Tap on the specific account you want to turn S/MIME on for. Tap …

Sep 24, 2025 · Enabling cross-tenant access is the simplest workaround as it allows encrypted emails you send to other external tenants to be opened successfully. To do this, follow these …

S/MIME provides encryption, which protects the content of e-mail messages, and it provides digital signatures, which verify the identity of the sender of an email message.