My mother is experiencing issues with Mail: she is constantly being told that the server imap.gmail.com is not verified. The certificate was issued by FortiGate CA, which is apparently not the right certificate for Gmail. When I check in the KeyChain, I do not find such a certificate. Thus, I do not know what do to. And I see that quite a few people faced the same issue, but no one posted a solution to get rid of it. I am thinking of reinstalling everything of her iMac. But before I do so, do you see another solution?