I have done testing on the sandbox and I get a response each time even though I have not installed the listed certificates on the notification for the live change on Tuesday. I did however, find these certs already in the CA file on the sever and wanted to verify this will still work come Tuesday:

Entrust 2048 SHA-1 Root* Entrust OV SHA-1 2048 root 38 63 DE F8 7/24/2029
L1K Root (EV Root) Entrust EV SHA-1 2048 root L1Kroot.txt 45 6B 50 54 11/27/2026

Root 9 - GeoTrust Global CA2

Root 3 - GeoTrust Primary Certification Authority

Root 4 - GeoTrust Primary Certification Authority – G2

Root 5 - GeoTrust Primary Certification Authority – G3

Root 6 - GeoTrust Universal CA

Root 2 - GeoTrust Global CA

CyberTrust Cert Exp 5/12/2025 serial  33554617

CyberTrust Cert Exp 8/13/2018 serial 421

I just want to make sure we are good to go on Tursday. We currently use Auth for e-commerce purchases only, no api via an app.