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Outlook giving security alert message regarding certificate.

Anonymous
2024-06-03T18:44:37+00:00

Hello, I'm IT support for a small company. I'm reaching out to the community in regards to this message that pops up only for two people in the entire company; everybody else does not receive the following message.

Security Alert

mail.company.com
Information you exchange with this site cannot be viewed or

changed by others. However, there is a problem with the site's security certificate.

❌ The security certificate was issued by a company you have not

  chosen to trust. View the certificate to determine whether you 

  want to trust the certifying authority.

✅ The Security certificate date is valid.

❌ The name on the security certificate is invalid or does not match

  the name of the site.

Do you want to proceed?

Yes No View Certificate....

Like i mentioned before, only two people in the entire company has this issue and everybody else's is normal and does not have this message. I did click on the "View Certificate" and inspected its properties. The certificate is valid and the issuer is Unifi.local.

Outlook | Windows | New Outlook for Windows | For home

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  1. Anonymous
    2024-06-03T21:21:40+00:00

    Hello Leonel Romo

    Thanks for the feedback. You should back up the registry key data only. You can back it up in your computer. Regarding the certificate,

    the best approach is to either generate a new self-signed certificate or obtain a trusted emails/client certificate from a CA and install it.

    This will ensure that your clients can connect without any security warnings. Kindly search for a trusted certificate Authority (CA) organization that

    issues digital certificates. (www.digicert.com).

    Hope this helps! Please feel free to post back or submit your comments and vote to make this thread superior content and help any other users

    in the community who may be facing a similar scenario to easily find this thread/post.

    Sincerely,

    Bertrand

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  2. Anonymous
    2024-06-03T20:41:30+00:00

    Hello and yes i did see a Unifi.local certificate installed on the user's computer. The certficate has not expired and is still valid. After doing some online research Unifi is not a trusted certificate and am not sure how to obtain a new one. I haven't checked the name to see if it matches to the mail server since I don't have access but the System administrator does. I have not tried modifying the registry key yet but will try that. By back up, did you mean just a general backup of the computer or the registry key? Also where would I obtain a new certificate?

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  3. Anonymous
    2024-06-03T20:27:34+00:00

    Hello Leonel Romo

    Thank you for reaching out to Microsoft support.

    It sounds like the issue you are experiencing is related to a security certificate error in Outlook. This error message usually appears when

    the certificate used by the mail server is not trusted by the client computer. Kindly check and confirm the following.

    1. Did you check if the certificate is installed on the client computer? If not, install the certificate on the client computer.
    2. Did you check if the certificate is expired. If it is, renew the certificate?
    3. Did you check if the certificate is issued by a trusted certificate authority? If not, obtain a certificate from a trusted certificate authority.
    4. Did you check if the name on the certificate matches the name of the mail server? If not, obtain a certificate with the correct name.
    5. Have you deleted tried manually delete the following registry key?

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates (Please back up and exercise caution when modifying the registry)

    Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

    Awaiting your valuable response.

    Sincerely,

    Bertrand

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