You receive the following Error event in the event log in Microsoft Exchange Server 2013 Client Access Server or in Microsoft Exchange Server 2016 Mailbox Server:
Log Name: Application
Event ID: 3018
Task Category: Extension
Scenario: GetConfig.GetConfig. The request failed. Mailbox: Url: https://o15.officeredir.microsoft.com/r/rlidMktplcWSConfig15 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 188.8.131.52:443
If the server that's running Exchange Server has an internet connection, check the proxy server to see whether the following URL is enabled for access:
If the server does not have an internet connection, you can safely ignore this error message. Or, you can use the following method to reduce the probability of the error occurring in the future.
Change the interval for the Office Store access checks
Open the following Web.config files in the Exchange Server 2013 Client Access Server or Exchange Server 2016 Mailbox Server:
In Microsoft Exchange Server 2016, you must also change the REST Web.config file: %ExchangeInstallPath%ClientAccess\rest\web.config
C:\Program Files \Microsoft\Exchange Server \V15\ClientAccess\exchweb\ews\web.config
C:\Program Files \Microsoft\Exchange Server \V15\ClientAccess\Owa\web.config
C:\Program Files \Microsoft\Exchange Server \V15\ClientAccess\rest\web.config
In each Web.config file, add the following line between the "<appSettings>" line and the </appSettings> line.
<add key = "KillBitRefreshTimeInSeconds" value = "<seconds>" />
For example, the following line sets the interval for Office Store access checks to 86,400 seconds (1 day):
<add key = "KillBitRefreshTimeInSeconds" value = "86400" />
From the administrative tools, start Internet Information Services (IIS) Manager.
Select Application Pools, right-click each of the following pools, and then click Recycle: