Error during migration process: "Could not connect to http://SERVER_NAME:8888/ImportSession.svc. (4284750)

When testing connection, the following error is returned:
"System.ServiceModel.EndpointNotFoundException: Could not connect to http://SERVER_NAME:8888/ImportSession.svc. TCP error code 10061: No connection could be made because the target machine actively refused it IP_address:8888. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it IP_address:8888
at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.InternalConnect(EndPoint remoteEP)
at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.GetRequestStream()
at System.ServiceModel.Channels.HttpOutput.WebRequestHttpOutput.GetOutputStream()"

Incorrect configuration of the Notes Migrator for SharePoint Import Service

Please verify if both Notes Migrator for SharePoint web site and app pool is running (via IIS Manager) and check the identity used by the Import Service application pool and ,in case of AD account, specify this user within NMSP Services configuration at the Central Admin page