WebEx Bypass HTTPS Scanning on a Sophos UTM

Question

Hi, I'm running Sophos UTM 9 with decrypt and scan HTTPS traffic enabled. 
 WebEx works fine when I turn off SSL Scanning for a machine, but I'm having trouble find all the URLs that WebEx uses; so that I can exclude them from the SSL Scanning . 
 Below are all the URLs that I have found within the Web Filtering logs. 
 ^.*\.webex\.com
^.*\.webexconnect\.com
^.*\.ciscowebex\.com
https://62.109.231.15/ https://webex.tt.omtrdc.net/ 
 
 I have created a rule to exclude these URLs from the SSL Scanning but WebEx still doesn't work. I can't see anymore URL present in the logs or see anything being block in the Firewall , Application Control or Intrusion Prevention System logs. 
 Have I missed something here? Has anyone else got WebEx working through a Sophos UTM with HTTPS Decrypt and Scan enabled? 
 Any help is appreciated.

RichardOsborn · Accepted Answer

I have found a solution after using a packet sniffer on the WebEx application. 
 I was able to obtain all the subnet that WebEx is using and exclude them from the SSL Scanning using the following expressions. 
 https:\/\/62\.109\.204\.[0-9]{1,3} https:\/\/62\.109\.224\.[0-9]{1,3} https:\/\/62\.109\.230\.[0-9]{1,3} https:\/\/62\.109\.231\.[0-9]{1,3} https:\/\/62\.109\.232\.[0-9]{1,3} https:\/\/62\.109\.234\.[0-9]{1,3}