Hello

Images in emails in Outlook have suddenly stopped working if the link is HTTPS and instead show the red X when using Outlook internally.

Software is:

Microsoft Exchange 2013 SP1 running on a Windows Server 2012 R2 server.

Outlook is 2013 SP1

Externally clients that use Outlook Anywhere can view images correctly and it is only internal clients where it has stopped working.

Normally machines don't use the TMG server as the gateway or as a proxy in IE but I have tried both and it makes no difference.

The error that seems to be getting logged in TMG is:

Closed Connection
Log type: Firewall service 
Status: A connection was abortively closed after one of the peers sent an RST packet.  
Rule: Allow Web Access for All Users 
Source: Internal (192.168.1.99:55069) 
Destination: External (www2.twitter.jp 199.59.149.201:443) 
Protocol: HTTPS 

This is just the last email I clicked on but all the rest are the same. If the image is just http then it loads. I have checked the email server and can browse the internet fine and view images over HTTPS. I can also browse images over HTTPS on the client with TMG as the Gateway so I'm not sure what it could be.

HTTPS inspection is disabled as well.

Thanks

Robin

Hi,

Please use TMG Data Packager to troubleshoot this problem.

http://blogs.technet.com/b/brennan-crowe/archive/2011/03/02/using-tmg-data-packager-to-troubleshoot-exchange-web-lync-web-and-sharepoint-connectivity.aspx

Best Regards,

Joyce

Make sure that the Security Zone within the settings of Outlook (not IE, but Outlook itself) is set to Internet rather than Restricted.  For some reason Outlook periodically resets itself back to Restricted,...maybe caused by patches being applied from Windows Update/Automatic Update, dunno.  I've never figured out why it happens,...I just know it does, and when it does, we start getting the Red X in place of the linked images when viewing mail in Outlook.

"...the peers sent an RST packet"

RST Packet means a "Reset Packet",...and the Peer I believe is Outlook in this case.  So basically it is Outlook saying "Bye-Bye" and "hanging up the phone".

Anyway, I don't know for sure if it is your problem, but I know it happens to us a lot,...except in our case it happens no matter if it is HTTP or HTTPS.

• Edited by Phillip Windell 13 hours 3 minutes ago Cleaning up Typos as usual

Make sure that the Security Zone within the settings of Outlook (not IE, but Outlook itself) is set to Internet rather than Restricted.  For some reason Outlook periodically resets itself back to Restricted,...maybe caused by patches being applied from Windows Update/Automatic Update, dunno.  I've never figured out why it happens,...I just know it does, and when it does, we start getting the Red X in place of the linked images when viewing mail in Outlook.

"...the peers sent an RST packet"

RST Packet means a "Reset Packet",...and the Peer I believe is Outlook in this case.  So basically it is Outlook saying "Bye-Bye" and "hanging up the phone".

Anyway, I don't know for sure if it is your problem, but I know it happens to us a lot,...except in our case it happens no matter if it is HTTP or HTTPS.

• Edited by Phillip Windell Thursday, April 24, 2014 9:49 PM Cleaning up Typos as usual