Good day All,

I have 3 Exchange servers 

EX01(Exchange 2010)
EX02(Exchange 2013)
EX03((Exchange 2013)

E-Mails flow through Edge Transport server 2013

I don't understand why I'm not able to open OWA externally, also mobie devices stopped sending/receiving e-mails.

External address in OWA settings is correct.

Before that I had only Exchange 2010 server installed and everyring worked well. But after Installation of Edge transport server and 2 other Exchange 2013 servers I faced with this issue.

Does anyone know what might that be?

Thank you in advance.

Is the domain pointing to your external IP?
Have you tested the port is open on the firewall?

If it's working internally, then it might be a firewall issue, or the domain isn't pointing to the correct External IP.

The thing is when I point NAT in Firewall to Exchange 2010(instead of Edge) everything becomes normal. The problem appears when I point NAT to Edge transport server

OWA is maintained under the Client Access Role. That is, NAT should translate OWA to the CAS instead of the FrontEnd server. Second, in a 2010+2013 coexistence some more adjustment should be considered. For example, see here: http://exchangequery.com/2014/09/24/owaews-configuration-in-exchange-20132007-coexistence/

Hi Santarem,

Agree with u.jan, you should point NAT to exchange 2013 CAS role instead of the Edge role.

In addition, you can refer to the following article to configure the Edge transport server: 

Exchange 2013 SP1: Edge Transport Server Installation and Configuration

Best regards,

OWA is maintained under the Client Access Role. That is, NAT should translate OWA to the CAS instead of the FrontEnd server. Second, in a 2010+2013 coexistence some more adjustment should be considered. For example, see here: http://exchangequery.com/2014/09/24/owaews-configuration-in-exchange-20132007-coexistence/

• Proposed as answer by Niko.ChengMicrosoft contingent staff, Moderator 22 hours 8 minutes ago