When using the following: <outbound> <pass-through-router> <outbound-endpoint address="http://myuserid:mypassword@somehost.example.com/myservice" remoteSync="true" /> </pass-through-router> </outbound> Mule 2.1.0 does not use the user id and password specified in the address attribute. As a result, if the somehost.example.com enforces basic authentication, it results in a HTTP 401 error. I got it to work when I add the following line to the org.mule.transport.http.HttpClientMessageDispatcher.doDispatch() method: connector.setupClientAuthorization(event, httpMethod, client, endpoint); After the change, the method looks like this: protected void doDispatch(MuleEvent event) throws Exception { HttpMethod httpMethod = getMethod(event); connector.setupClientAuthorization(event, httpMethod, client, endpoint); try { execute(event, httpMethod); if (httpMethod.getStatusCode() >= ERROR_STATUS_CODE_RANGE_START) { logger.error(httpMethod.getResponseBodyAsString()); throw new DispatchException(event.getMessage(), event.getEndpoint(), new Exception( "Http call returned a status of: " + httpMethod.getStatusCode() + " " + httpMethod.getStatusText())); } } finally { httpMethod.releaseConnection(); } } Now it is adding basic authentication credentials to the request to the somehost.example.com server, and it is working fine.