I have had this working for some time and previously configured libraries with incoming email continue to function, however, when I attempt to assign an Email address to a previously unconfigured library, I receive an error (Something went wrong). ULS errors show:
ListUpdate Failure: System.Net.WebException: The request failed with HTTP status 401: Unauthorized.
at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
at Microsoft.SharePoint.DirectorySoap.SPDirectoryManagementProxy.DeleteContact(String Alias, String Requestor)
at Microsoft.SharePoint.SPList.UpdateDirectoryManagementService(String oldAlias, String newAlias)
at Microsoft.SharePoint.SPList.Update(Boolean bFromMigration)
Application error when access /_layouts/15/EmailSettings.aspx, Error=The request failed with HTTP status 401: Unauthorized.
at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
at Microsoft.SharePoint.DirectorySoap.SPDirectoryManagementProxy.DeleteContact(String Alias, String Requestor)
at Microsoft.SharePoint.SPList.UpdateDirectoryManagementService(String oldAlias, String newAlias)
at Microsoft.SharePoint.SPList.Update(Boolean bFromMigration)
at Microsoft.SharePoint.ApplicationPages.EmailSettingsPage.SubmitButton_Click(Object sender, EventArgs args)
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
I have ensured that the central admin app pool as well as the application app pool are running under the same, farm-admin account, which is also in the domain admin group. I have wire-sharked the connection to verify that it is querying AD and is not generating errors in that direction. I can find no reason that it would be getting a 401 error. I have also attempted to update the list via powershell, where I get the same 401 unauthorized error.
Does anyone have any suggestions where else I might look to overcome this?