I can fully understand your concerns, however, since we are Microsoft 365 for Business support team, based on my knowledge and experience, this option to send encrypted message via S/MIME is generally available for Microsoft 365 for business users, * We are happy and always here to help you, and share the Microsoft 365 for business online information with you. Jennifer * Beware of scammers posting fake support numbers here.

Your understanding and cooperation will be highly appreciated. To help you further under this circumstance, it is recommended that you may contact Yahoo account support team for further confirmation.

To send encrypted message, then a possible reason is S/MIME may not be available for your account. Moreover, if we want to encrypt message with Microsoft 365 Message Encryption (Information Rights Management), the sender must have Microsoft 365 Message Encryption, which is included in the Office 365 Enterprise E3 license.įor your reference: Encrypt email messages.īut according to your description, you are subscribing to Microsoft 365 personal subscription, therefore, you will not be able to encrypt message with Microsoft 365 Message Encryption (Information Rights Management).īesides, since you are using Yahoo account in Outlook, if you have correctly set up to use S/MIME encryption but still have the problem Is supported only on messages sent to and from recipients in your organization’s address list.

Based on my knowledge, to send encrypted message in Outlook via S/MIME encryption, it is required the sender and recipient must have a mail application that supports the S/MIME standard.

Zoho outlook issues encryption