Dear All . 

we have exchange server 2013 RTM currently single server and when trying to access out from out side we are getting ERR_CONNECTION_CLOSED and sometimes it is working and sometimes it is not .

also sometimes from IE Browser it is working and from Google Chrome it is not !!

is this something related to the Certificate ? 

where to start troubleshoot !!

update exchange to CU7 will solve the issue !

owa working internally and no problem 

also recently we have renews the SAN Certificate .

• Edited by JavaHeart 20 hours 47 minutes ago

If you're Exchange server is still RTM, I highly recommend updating it to CU7 or CU8. Beyond that, you can use the Remote Connectivity Analyzer to assist you in t/shooting your external OWA issue. https://testconnectivity.microsoft.com/

thanks B0ndoo7 for you help ,

can you please tell me which option i should select to test the owa from outside ?

What firewall or other devices are in front of the Exchange server ? Is this 1:1 NAT or port forwarding ?

we have Mcafee Firewall 

Mcafee has an SSL content inspection option. Can you disable this temporarily and see if that improves the connection ? 

"If your particular SSL application doesn't work when SSL content inspection is configured, it may be incompatible. Use passthrough instead for the SSL application. To use passthrough, configure a new SSL policy rule for the endpoints in the audit message with an action of No Decryption, and then place that rule above your Re-encrypt rule."

• Edited by Knob Country 16 hours 52 minutes ago

You can use the ActiveSync test to see if there's any failures; if there are, they can help point you in the right direction for fixing OWA.  I'd also follow Knob Country's suggestion too with your firewall.

 i have run the activeSync test and below is the result :

	The Microsoft Connectivity Analyzer is testing Exchange ActiveSync.
	Exchange ActiveSync was tested successfully.
	Additional Details
	Test Steps

there is no errors and this warning regarding Windows OS phone . and for the firewall i have  disabled the SSL inspection and still the same . is there anything i have to do from the IIS Server Manager ! bind the certificate or have some options to be enabled there ?