If it is not, change it and then try connecting again.Then, click on “ Issued to Name” and make sure that the name there is the same as the name of the mail server.Once you get the error, click on View Certificate.To do that, follow the given instructions: The first solution that you have to look for is that the name of the certificate in MS Outlooks is same as of the mail server. Now, in order to fix the issue, you can use the solutions given down below. If your MS Outlook’s certificates are not valid for the mail server that you want to connect to, then you will get this error.

Certificate issues: Sometimes, invalid certificates between the mail server and the email client can cause this issue.Time/Date Issue: If your computer’s day/time is not correct, that might result in this error message.As wrong port numbers mean no connection of the email client and the mail server. Wrong Ports in Configuration: If you have entered the wrong port numbers for your mail server while you were configuring an account, then you are going to get this error.Ports Blockage: If you are in a school or university or any other such place which is under restrictions and some of the SSL ports which MS Outlook’s email client uses are blocked, then you will not be able to connect to the email account and you will get this error.ISP Changed the mail server’s name: Another cause would be that the ISP has changed their mail server i.e its name and thus, you are being redirected from an old address to new ones, and that new address is not in their SSL certificate list.Wrong Hostname: Many times, when users are configuring MS Outlook for a new account, they mistakenly type the hostname wrong and since when the hostname is wrong, there is no chance of any connection.

Outlook your connection is not private