I'm experiencing a weird issue with one of our users trying to send encrypted emails. They keep getting an error message that says "Missing Certificates," stating that valid certificates weren't found for the recipients. This happens whether the recipients are internal or external. We're not using an SMIME setup; we're just relying on the built-in encryption in Office 365. I've checked a few things: the user has a Business Premium license, and I tested sending the emails through both the new webmail and the classic version with the same results. I also verified that the SMIME settings in both versions are turned off. When I checked using PowerShell, both UserCertificate and UserSMIMECertificate returned null for this user. I created a registry key to suppress name checks, rebooted, but the issue persists. Additionally, I confirmed there are no email rules or policies affecting the user. The only thing I haven't tried yet is uninstalling and reinstalling Office 365 since the problem occurs in the Outlook Web App too. Any advice on how to fix this error?
2 Answers
Sounds like the user might be thinking they need SMIME enabled to send encrypted emails. They only need to use the encrypt option when composing a new message. You can do this in Outlook by going to 'Options' and selecting 'Encrypt' and then 'Encrypt-Only.' Double-check that the mail encryption option isn't enabled in Outlook settings. Here's a link that might help: https://support.microsoft.com/en-us/office/set-up-outlook-to-use-s-mime-encryption-2e57e4bd-4cc2-4531-9a39-426e7c873e26
To clarify, is the user facing this issue when trying to encrypt a new email or when replying? The error message can vary based on that, and knowing might lead to more targeted solutions.
It's when they send a new email, and the error message mentions that valid certificates weren't found for the recipients.
Good point! It's worth confirming those settings. Also, what exactly happens when they're composing the email? Is it a new message or a reply?