My problem is i can't connect to outlook from the PCS that out of my domain in another word the the auto discovery working correctly but I can't connect to outlook for my mailbox from a pc that isn't a domain joined and also the outlook anywhere isn't working correctly for my external DNS zone and here u are the exchange 2013 deployment scenario :
1- I have 3 exchange 2013 servers (CAS and two CAS/Mail servers working with DAG ) for my domain called citc.com
2-The CAS has a certificate that have SANS of CAS.citc.com and CAS.citc.local (the citc.local will work as external DNS zone for my external internet clients and already i hold that zone on my internal DNS )
3- 2 primary dns zones one for my domain(citc.com) and the other(citc.local) for my external dns zone for connecting the external clients to outlook
4-2 Databases belongs to the DAG
5-modified the virtual directories for my CAS exchange server AS follow:
Set-OwaVirtualDirectory -Identity "cas\owa (Default Web Site)" -InternalUrl https://cas.citc.com/owa -ExternalUrl https://cas.citc.local/owa
Set-EcpVirtualDIrectory -identity "ecp (Default Web Site)" -InternalUrl https://cas.citc.com/ecp -ExternalUrl https://cas.citc.local/ecp
Set-ActiveSyncVirtualDirectory -Identity "cas\Microsoft-Server-ActiveSync (Default Web Site)" -InternalUrl https://cas.citc.com/Microsoft-Server-ActiveSync -ExternalUrl https://cas.citc.local/Microsoft-Server-ActiveSync
Set-OabVirtualDirectory -Identity "cas\OAB (Default Web Site)" -InternalUrl https://cas.citc.com/oab -ExternalUrl https://cas.citc.local/oab
Set-ClientAccessServer -Identity cas -AutodiscoverServiceInternalUri https://cas.citc.com/Autodiscover/Autodiscover.xml
Set-WebServicesVirtualDirectory -Identity "cas\EWS (Default Web Site)" -InternalUrl https://cas.citc.com/EWS/Exchange.asmx -ExternalUrl https://cas.citc.local/EWS/Exchange.asmx
and the outlook anywhere for external host name as cas.citc.local and internal host name cas.citc.com
I repeat ( this an experential scenario) and i can connect correctly to my mailbox using OWA and even using outlook from a domain joined pc but i can't from a non-domain joined pc or an external client using outlook anywhere