How to get Outlook 2010+ to connect up externally using Outlook Anywhere (EXCH2013)?

Question

I have a on-premise EXCH2010 / EXCH2013 deployment and I would like to allow our users to be able to access their email using their domain joined and non-domain joined (workgroup) laptop/outlook.
The clients are running Outlook 2010 and/or Outlook 2013.
The current issue is that I cannot connect, my test case is using Outlook 2013 trying to connect externally (using autodiscover). When I go and add a new profile and I select Exchange and enter my server URL (the autodiscover urL) and my user-id and click
"check name" I get nothing, just an error saying lookup failed.
I would expect for a WORKGROUP computer to get prompted for user/pass so they can get authenticated and the profile added.
Here is my OutlookAnywhere settings in my AD.
RunspaceId                         : cd27e542-1c8b-4569-b62d-cb8a19a745a4
ServerName                         : exch-server
SSLOffloading                      : False
ExternalHostname                   : webmail.mydomain.com
InternalHostname                   : 
ExternalClientAuthenticationMethod : Ntlm
InternalClientAuthenticationMethod : Ntlm
IISAuthenticationMethods           : {Ntlm}
XropUrl                            : 
ExternalClientsRequireSsl          : True
InternalClientsRequireSsl          : False
MetabasePath                       : IIS://exch-server.xand1.mydomain.com/W3SVC/1/ROOT/Rpc
Path                               : C:\Windows\System32\RpcProxy
ExtendedProtectionTokenChecking    : None
ExtendedProtectionFlags            : {}
ExtendedProtectionSPNList          : {}
AdminDisplayVersion                : Version 14.3 (Build 123.4)
Server                             : exch-server
AdminDisplayName                   : 
ExchangeVersion                    : 0.10 (14.0.100.0)
Name                               : Rpc (Default Web Site)
Identity                           : exch-server\Rpc (Default Web Site)
Guid                               : e2325c87-eb52-49cb-ab18-f02a76e07340
ObjectCategory                     : xand1.mydomain.com/Configuration/Schema/ms-Exch-Rpc-Http-Virtual-Directory
ObjectClass                        : {top, msExchVirtualDirectory, msExchRpcHttpVirtualDirectory}
OrganizationId                     : 
OriginatingServer                  : xan-dc02.xand1.mydomain.com
IsValid                            : True
ObjectState                        : Changed
RunspaceId                         : cd27e542-1c8b-4569-b62d-cb8a19a745a4
ServerName                         : exch-server01
SSLOffloading                      : True
ExternalHostname                   : webmail.mydomain.com
InternalHostname                   : webmail.mydomain.com
ExternalClientAuthenticationMethod : Ntlm
InternalClientAuthenticationMethod : Ntlm
IISAuthenticationMethods           : {Ntlm}
XropUrl                            : 
ExternalClientsRequireSsl          : True
InternalClientsRequireSsl          : True
MetabasePath                       : IIS://exch-server01.xand1.mydomain.com/W3SVC/1/ROOT/Rpc
Path                               : C:\Program Files\Microsoft\Exchange Server\V15\FrontEnd\HttpProxy\rpc
ExtendedProtectionTokenChecking    : None
ExtendedProtectionFlags            : {}
ExtendedProtectionSPNList          : {}
AdminDisplayVersion                : Version 15.0 (Build 847.32)
Server                             : exch-server01
AdminDisplayName                   : 
ExchangeVersion                    : 0.20 (15.0.0.0)
Name                               : Rpc (Default Web Site)
Identity                           : exch-server01\Rpc (Default Web Site)
Guid                               : 4f20a6e4-ed74-4d75-8e6b-43fb0687848a
ObjectCategory                     : xand1.mydomain.com/Configuration/Schema/ms-Exch-Rpc-Http-Virtual-Directory
ObjectClass                        : {top, msExchVirtualDirectory, msExchRpcHttpVirtualDirectory}
OrganizationId                     : 
OriginatingServer                  : xan-dc02.xand1.mydomain.com
IsValid                            : True
ObjectState                        : Changed
Any idea how to make it work? We use Split DNS and one DNS entry for both internal/external clients (webmail.mydomain.com).

Answer 1

Hi,
Please verify whether you can logon OWA successfully.
If OWA works well, it seems there is no problem when access mailbox directly.
Then I suggest configure Outlook as following blog:
Manual configuration guide for Outlook 2013 in Windows 8 (Exchange 2013)
http://support.sherweb.com/Faqs/show/manual-configuration-guide-for-outlook-2013-in-windows-8-exchange-2013
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Thanks
Mavis
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