Hi Shelby,
Thank you for your inquiry and welcome to Centrify.
From the information you given, there are a few points that might have this failed:
1. The certificate that you imported, they are actually not needed to be trusted manually. If they need to be trusted manually, that means this should have something wrong with the cert itself or you did not import the DoD certs for those certs.
2. Have you imported the DoD certs into system keychain? It is because since 10.12, Apple dropped the SystemCACertificate.keychain, which means you will need to import all the DoD Certificates into System Keychain for now. You can have more details regarding this issue in the below thread:
3. From the output of the email, it indicated that the secure connection is not able to established, it is very likely the issue was the certificates not able to recognised due to 1 & 2 above.
4. For the time out error, have you checked with the GKO website on if they have any issues on this? But could you also upload us a system log that with this issue reproduced and we could have a check as well? It is because either the timeout happened when trying to connect to the website or timeout during finding the certificate in the mac.
Also, we wanted to know if you have this working in other macs? Thank you.
Best Regards,
Albert