Cisco ESA not connecting to Windows Exchange Server 2016

[thaqilaura0]

Dear community, 

I am trying to integrate Cisco ESAv in front of my Exchange 2016 Server. However, in the Connector in Exchange Server, I get the following error: error communicating with target host- Unable to connect -> SocketConnectionRefused: Socket error code 10061. 

I can see traffic of port 25 in the Firewall, allowing communication. There is no authentication in between the Exchange server and the ESAv. 

Can someone please share any troubleshooting idea? 

FW and AV are rules out so far. 

Looking forward to hearing from you. 

Thank you,

Laura 

[thaqilaura0]

Note: The Outbound traffic is not working. Meanwhile the inbound traffic, is working ok. 

[Ken Stieers]

Typically you will set the esa up with two listeners one for inbound mail, one for outbound mail. Each listener gets its own Host Access Table.

Go to Mail Policies/ HAT OverView. In the top line of the grid pick the outbound listener, add the ip of the Exchanger server to the "Relay" sender group.

[thaqilaura0]

Hi @ken 

With some more troubleshooting, I found out the Outbound Listener in ESA side is sending RST to the connection attempt of the Exchange Server. 

I am using a Bidirectional listener for inbound and outbound. The outbound is set to Relay, and the inbount to Accept. 

Any idea how I can further check the why ESA is termination the connection attempt with a RST? 

Thank you,

Laura  

[Ken Stieers]

Hey Laura, 

Go to your HAT

:

Pick the Outbound listener, and add your Exchange server ips to the Relaylist sender group.  Sumbit,and commit it.