We have successfully installed CRM Email Router 2016. Our CRM application is CRM online 2016 version. We have configured the outgoing profile. And also configure deployment option to connect to CRM 2016 online. URL is disco.crm.dynamics.com/OrgName and provided service account user name and password. Service account is having system admin role in CRM. When we click on load data we are getting below error.

The E-mail Router Configuration Manager was unable to retrieve user and queue information from the Microsoft Dynamics CRM server. This may indicate that the Microsoft Dynamics CRM server is busy. Verify that URL 'dev.crm.dynamics.com/CrmOrgName' is correct. Additionally, this problem can occur if specified access credentials are insufficient. To try again, click Load Data. (GetAuthState() - Request Status:.).

Event log error

#26234 - The Email Router service could not process a provider work item using assembly: Microsoft.Crm.Tools.EmailProviders.dll and class: Microsoft.Crm.Tools.Email.Providers.SmtpPollingSendEmailProvider. Microsoft.Crm.Passport.IdCrl.IdCrlException: GetAuthStateEx() - Request Status: at Microsoft.Crm.ServiceProxyCache`1.BuildServiceProxy(Uri serviceUrl, Credential credentials, Uri homeRealmUrl, String passportEnvironment, String onlineServiceEnvironment, IServiceConfiguration`1 serviceConfiguration) at Microsoft.Crm.ServiceProxyCache`1.GetNewServiceProxy(Uri serviceUrl, Credential credentials, Uri homeRealmUrl, String passportEnvironment, String onlineServiceEnvironment) at Microsoft.Crm.Tools.Email.Providers.Utility.BuildOrganizationService(Uri organizationServiceUrl, String authMode, Credential credentials) at Microsoft.Crm.Tools.Email.Providers.CrmPollingSendEmailProvider.Run() at Microsoft.Crm.Tools.Email.Agent.ServiceCore.ExecuteProviderWork(Object providerQueueRequestObject)

When we are using any particular user credential instead of service account it is working fine. However when we used service account it is giving this error.