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
Source: MSExchangeApplicationLogic
Date: <Date>
Event ID: 3018
Task Category: Extension
Level: Error
Keywords: Classic
User: N/A
Computer: CAS.contoso.com
Description:
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 65.55.69.140:443
Source: MSExchangeApplicationLogic
Date: <Date>
Event ID: 3018
Task Category: Extension
Level: Error
Keywords: Classic
User: N/A
Computer: CAS.contoso.com
Description:
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 65.55.69.140:443