Like most companies, my organization uses a proxy for all internet traffic. This presented a problem when we tried using Add-ins for Exchange 2013. At the time we could not figure out how to get the subsystem that pulled down apps in Exchange to use the proxy server despite trying the following methods
· Configuring the proxy in IE
· Setting the proxy at the Exchange server level via set-exchangeserver -internetwebproxy
· Using netsh or proxycfg
Since it was not needed at the time we migrated to Exchange 2013, I dropped the effort. Recently though, after we migrated to 2016, an actual request came in for an app from the Office Outlook app store. Since the servers could not get through the proxy we would see errors in the applications logs (Event ID 3018, see below for an example) and we would get errors every time we tried to add an app via the EMS or EAC. In regard to the Event log error, we would see a different URL referenced each time. When we logged into the Exchange host we could easily get to the URL in Internet Explorer (as along as long as our company’s proxy settings were in place) but the Exchange server could not reach it
Log Name: Application Source: MSExchangeApplicationLogic Date: 11/19/2017 1:13:29 AM Event ID: 3018 Task Category: Extension Level: Error Keywords: Classic User: N/A Computer: xchsrv01.contso.com Description: Scenario[ServiceHealth]: GetConfig. CorrelationId: e0bc58ff-f87e-4f73-a3df-814b4681bbfb. The request failed. Mailbox: Url: https://officeclient.microsoft.com/config16?CV=15.1.1034.26&Client=WAC_Outlook&corr=e0bc58ff-f87e-4f73-a3df-814b4681bbfb Exception: System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 40.83.182.229:443 at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception) --- End of inner exception stack trace --- at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.<EndGetResponseCallback>b__1() Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="MSExchangeApplicationLogic" /> <EventID Qualifiers="49156">3018</EventID> <Level>2</Level> <Task>3</Task> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2017-11-19T06:13:29.933295500Z" /> <EventRecordID>993987</EventRecordID> <Channel>Application</Channel> <Computer>xchsrv01.contso.com</Computer> <Security /> </System> <EventData> <Data>GetConfig</Data> <Data>e0bc58ff-f87e-4f73-a3df-814b4681bbfb</Data> <Data> </Data> <Data>https://officeclient.microsoft.com/config16?CV=15.1.1034.26&Client=WAC_Outlook&corr=e0bc58ff-f87e-4f73-a3df-814b4681bbfb</Data> <Data>System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 40.83.182.229:443 at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception) --- End of inner exception stack trace --- at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.<EndGetResponseCallback>b__1()</Data> </EventData> </Event>
After some digging we found out that we needed to set the proxy for the account that is running the app pools for Exchange (which in most cases is LOCALSYSTEM) and that it needed to be set with bitsadmin /setproxysetting. When using this command you will be given a message that it is deprecated but I couldn’t find another method to set the proxy for the LOCALYSTSTEM account. Using bitsadmin You can configure the proxy either manually, like so
bitsadmin /util /setieproxy localsystem MANUAL_PROXY http://http-contso.com:80 "*.corp,contso.com; <local>"
Or using a PAC file
bitsadmin /util /setieproxy localsystem AUTOSCRIPT http://security/webproxy/BalaPAC.pac
We had trouble in our environment getting the PAC file to work with Windows Server 2012R2 and it worked half the time with Windows Server 2016. So, we stuck with the manual method. Our exclusions list was really long and apparently was too big for the buffer to read the settings back using
bitsadmin /util /getieproxy localsystem
Or you can check the following registry entry for to verify the setting took: HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections\DefaultConnectionSettings
After setting the proxy and restarting IIS, we could install Add-ins via PowerShell and the EAC. Though occasionally we still get the 3018 Application log errors for some URLs, but at least we can now install Add-ins.
