Unable to fetch the certificate from the server – There are times when the name on the security certificate is invalid or doesn’t match the name of the site.Select the email again at the top of the page. So, this issue happens because of your iPhone’s strict confirmation of your mail server authentications. Tap General and navigate to Profiles and Device Management. As one of the most professional System Repair tools, AnyFix can fix more than 100+ iPhone/iPad OS problems and 200+ iTunes errors, including iPhone crash, iPhone keeps restarting, iTunes won’t connect to iPhone and so on.However, to complete the installation process, have both Sign and Encrypt by Default set to Yes. Safari could not open the page because the server stopped responding.On your computer, export your Exchange Server Certificate by following the steps below: Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. Mail server certificate is invalid iphone Select Settings > Mail > Accounts.