Hello Guys.

I really hope someone can help me resolve this asap. I have spent hours upon hours pouring through blogs and forums and applied and double checked every conceivable autodiscover tool and can not resolve this.

Scenario: Server 2012 Standard with Exchange 2013. Split-Brain DNS, (Internal = domain.local) (External = mail.domain.com.na)

I have applied CNAME, PTR, SRV and Autodiscover.xml, but still Exchange Connectivity (Autodiscover) keeps failing on all points.

Everything else is working 100%, OWA, Activesync, IMAP etc.

But I have 1 client PC with Windows 8 Single Language that can obviously not join the domain, and the client doesn't want to use IMAP saying it looks different?? Don't know why. But he wants to use Exchange.

From outlook 2013 I configure it as follows:

Server: server.domain.local

Username: domain user account

Exchange Proxy Server: mail.domain.com

Connection: SSL, HTTP and HTTPS, authentication "auto negotiate"

It just comes back with "Unable to resolve username"

Is it necessary to, as with "mail.domain.com" point "autodiscover.domain.com" to the public IP?

Thank you in advance.

Kind Regards

Hentie Loots

• Edited by EagleClaw1976 Sunday, July 05, 2015 2:26 PM

Hello Ed and thank you for the reply.

This is exactly where I get a bit hazy.

Some of the forums I have read talk about "internal" and "external" DNS Zones.

Internal is fine. But what do you mean by "External / Internet" DNS? Is it something my ISP has to setup on the internet dns? Like with the MX Records that point mail.domain.com to the public IP? Or is it a new zone I need to create on the Server's DNS? Reverse Lookup Zone or something?

I can't find anything on the web about "External DNS Zone". I completely lost with where exactly on this split-brain dns between .local and .com and Foreward and Reverse Lookup Zone I need to create the PTR, SRV, CNAME and A records.

Like I said, everything else works like a well oiled machine. It is only the Autodiscovery from the internet that keeps failing, so Outlook keeps saying exchange is offline and it wasn't able to resolve the username.

I get the same issue even when connected via VPN.

"The action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action."

Hoping to hear back soon.

Thanks again.

Hentie Loots

• Edited by EagleClaw1976 Sunday, July 05, 2015 7:14 PM

This is the response I get.

<Autodiscover>

<Response><Error Time="11:46:31.9846029" Id="2220214705">

<ErrorCode>600</ErrorCode>

<Message>Invalid Request

</Message><DebugData/>

</Error>

</Response>

</Autodiscover>

From what I saw with a quick google search, is that this is correct and normal?

• Edited by EagleClaw1976 Monday, July 06, 2015 10:54 AM

Hi Hentie,

You seem to be mixing\confusing things up. To list out look at the below requirements, let me know if you understand this first, then we can go on the configuration part internal then external one at a time.

It will be split brain DNS only if your internal name and external are same.

Below example considers that your roles are colocated on single server:

The following are examples of recommended DNS records that you should create to enable mail flow and external client connectivity.

FQDN	DNS record type	Value
Contoso.com	MX	Mail.contoso.com
Mail.contoso.com	A	172.16.10.11(or Public IP of the router which should point to the Ex2013 Mailbox+CAS server( and not the DC IP) on port 25 and 443)
Owa.contoso.com	CNAME	Mail.contoso.com
Autodiscover.contoso.com	CNAME	Mail.contoso.com

The following are examples of recommended DNS records that you should create to enable internal client connectivity.

FQDN	DNS record type	Value
Mail.contoso.com	CNAME	Ex2013.corp.contoso.com
Owa.contoso.com	CNAME	Ex2013.corp.contoso.com

You can add a autodiscover too if you like internally as well.

Go through The Exchange Server Deployment Assistant to confirm you have performed the all steps and correctly or not.

Few important things, are you using CAS and MBX on the same box. If not have you enabled CAS Proxying or not.Are you using a reverse proxy server and SMTP Gateway These factors will decide which IP your external IPs or the router to internel will be pointing to.

Normal implementations are like this.

External Autodiscover (A or CNAME)->Router\Firewall->Reverse Proxy Server->Firewall->CAS

External OWA (A or CNAME) ->Router\Firewall->Reverse Proxy Server->Firewall->CAS

External MX -> Router\Firewall->Edge\SMTP gateway->Firewall->MBX server

Internal MBX->Firewall->Edge\SMTP gateway->Firewall->Other domain SMTP s