Hi my exchange server name is Ex2013.mydomain.com and my urls are mail.mydomain.com and at isp my records are pointing to mail.mydomain.com
Servers Tab- virtual directory- configure External Access Domain.
I have gone with below settings,
Select external access domain : Ex2013 (here it should be ex2013 this is my current exchange 2013)
Enter the domain name you will use with ur external CAS: mail.mydomain.com(Is this OK?)
Are these settings correct, just to cross check