POST request not showing in the logs, for mail.google.com, even though SSL Visibility appliance successfully decrypts the traffic.
Investigating the sysinfo config, the following would may show up and the highlighted condition would prevent the POST request from showing up in the logs.
; If the server requests a client certificate, tunnel the SSL traffic via SSL proxy
define condition DetectProtoNo
Create following policy, to have the post logs are show up in proxy logs.
define condition Protocol_Detection