How to fix Invalid Certificate Microsoft Outlook cannot sign or encrypt this message because there are no certificates?

Question

Hi, I keep running into this issue

I saw this post https://answers.microsoft.com/en-us/outlook_com/forum/all/how-to-fix-invalid-certificate-microsoft-outlook/e6266784-6a83-4fd2-b6bb-22e2e1740ef8 

I disabled the signature option and I keep getting that error, Any assistance would greatly be appreciated

I was able to get that email to work in outlook 2019 no problem, the encryption add on is called egress

Answer 1

Dear Andres Rodriguez1,

Good day! Thank you for posting to Microsoft Community. We are happy to help you!

At first I would like to confirm with you:

• Is this the only account in your profile? The certificate can only be used to sign the one address.
• What type of email account do you have configured in Outlook? POP, IMAP, Outlook.com, or Microsoft Exchange?
• If you are using outlook desktop client, whether you met the same error when you used the same account to login OWA(outlook web app)

In addition, please kindly refer to:
"Change Security Settings" a pop out window appears titled "Security Properties". Under Security/Security setting I select my certificate from the drop down, and then click OK.

Besides it is recommended to try following steps to see if it helps:

1. Go to File > Trust Center > Microsoft Outlook Trust Center > Trust Center Settings > Trusted Publisher, delete the digital signature(s) if it is available in the list.
2. Then negative to Email Security , click Import/Export to import a digital ID from a file on your computer, or click Get digital IDs to find a list of services that issue digital IDs for your use, then check the result.

If your problem persists, please give me feedback on the information I need and the results of the above methods that you have tried, so that I can do more research to help you better.

Thanks in advance for your understanding! Your patience and cooperation will be highly appreciated. Hope you all the best!

Sincerely,

Kerry Chen | Microsoft Community Moderator

Answer 2

Hi Kerry thank you for the timely response

I looked over the screenshot you sent, and noticed "Encrypt contents and attachments for outgoing messages" was unchecked, and went to the outlook app and unchecked it and the email is working now!

Thanks for the help!