It is critical to justify issue that means the security certificate of your Outlook email server is using has invalid or expired for many reasons. The error code is shown as:
The server you connected to is using a security certificate that cannot be verified.
That means your Security certificate has expired. If you are an administrator of Microsoft Outlook then you should update the certificate and if you are end-user then you need to speak with its admin. Make sure one thing, you can’t turn it off or can’t hide the warning. But, it is safe to OK and connect to your mail server.
It is easy to fix Outlook certificate error that has technical knowledge, but it will become critical who don’t have any idea about it.
Target Principle name is incorrect:-
Let’s suppose you set up an SSL IMAP email account in Microsoft Outlook. At most, we get a popup when run the program that is “internet security warning”. The server which you want to connect by using a security certificate cannot be verified. The name of the target principle is incorrect. So, view the certificate. This security certificate is almost self-signed in so just click on Yes to continue by using the server/email account. But, how can I remember Outlook.
Outlook certificate error warning indicates that the server name does not match the name according to your account settings, in case of an exchange server that the address in the auto-discover file does not match the address which one the server use. Security certificate warning in Microsoft Outlook is a common problem when the administrator uses the self-published certificate.
If your mail provider supports other server names then change the server name which is an easy fix.
Follow the below-given steps to get your mail server’s IP address:
- Open the menu and type cmd to open a command prompt.
- For finding your IP address and the hosts server name enter ping mail.yourservername.com.
- If the ping results server name which matches the name on the certificate then use it as the mail server name in outlook.
- If it doesn’t match the name then ping the server name which used in the certificate. In case the IP address matches your mail server’s IP address then use it as the mail server name in Microsoft Outlook.
If your host does not have a server name then use the below-given steps to eliminate Outlook certificate error:
- In case, you don’t ping your server for the IP address then launch a cmd prompt and now ping your incoming mail server.
- After that, view the certificate as above and note down the server name under issued to.
- Now, edit the host file and add a new line for IP addresses 220.127.116.11 and the host file is in %windir%\system32\drivers\etc.
- Search for a notepad on the start menu to launch the hosts file.
- Now, right-click on it and click on run as administrator.
- Open dialogue, and paste the path to the hosts file.
- Click on all files as the file shown on the right.
- Now, you can see which entry you create in the hosts file.
- Edit Microsoft Outlook settings and change the incoming and outgoing mail server.