Set up Outlook to use S/MIME encryption - Microsoft Support
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.
Send S/MIME or Microsoft Purview encrypted emails in Outlook
Send S/MIME or Microsoft Purview encrypted emails in Outlook using a work or school account with a qualified Microsoft 365 subscription.
Open encrypted and protected messages - Microsoft Support
Learn how to identify and open encrypted and protected emails no matter what email client you're using.
Send encrypted messages with a Microsoft 365 personal or family ...
Encrypt: Your message stays encrypted and doesn't leave Microsoft 365. Recipients with Outlook.com and Microsoft 365 accounts can download attachments without encryption from Outlook.com or the …
Send a digitally signed or encrypted message for Mac
In an email message, choose Options, select Encrypt and choose the encryption option that has the restrictions you'd like to enforce, such as Do Not Forward or Encrypt-Only.
Learn about securing and protecting email messages in Outlook
Learn how to use encryption and other security settings to protect messages sent from Outlook.
Send S/MIME or Microsoft Purview encrypted emails in Outlook
Send S/MIME or Microsoft Purview encrypted emails in Outlook using a work or school account with a qualified Microsoft 365 subscription.
Secure messages with a digital ID in Outlook - Microsoft Support
To send and receive encrypted email messages, both the sender and the receiver must share their digital ID certificates with each other. Open a message that is digitally signed as indicated in the …
Error opening encrypted emails from classic Outlook: "Configuring your ...
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 steps:
View certificates - Microsoft Support
Outlook uses certificates in cryptographic email messaging to help keep communications secure. You can view your own certificates or those that you receive in email messages.