Не выполняется отправка email в workflow activity

[_AV_]

Всем доброго дня!

Не могу понять почему не выполняется SendEmailRequest.

Подскажите, плиз, куда копать?

CRM 4.0 RU8

namespace CRM_SendMailActivity
{
    [CrmWorkflowActivity("Send Mail")]
    public partial class SendMailActivity : SequenceActivity
    {
        protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
        {
            IContextService contextService = (IContextService)executionContext.GetService(typeof(IContextService));
            IWorkflowContext workflowContext = contextService.Context;
            ICrmService crmservice = workflowContext.CreateCrmService(true);
            Guid EmailId = new Guid(EntityIDIN);

            QueryByAttribute queryByAttribute = new QueryByAttribute();
            queryByAttribute.ColumnSet = new AllColumns();
            queryByAttribute.EntityName = EntityName.email.ToString();
            queryByAttribute.Attributes = new string[]{"activityid"};
            queryByAttribute.Values = new string[] { EmailId.ToString() };

            BusinessEntityCollection retrieved = crmservice.RetrieveMultiple(queryByAttribute);

            if (retrieved.BusinessEntities.Count == 0)
                return ActivityExecutionStatus.Canceling;

            SendEmailRequest sendrequest = new SendEmailRequest();
            sendrequest.EmailId = ((Key)((email)retrieved.BusinessEntities[0]).activityid).Value;
            sendrequest.TrackingToken = "";
            sendrequest.IssueSend = true;
            crmservice.Execute(sendrequest);

            return ActivityExecutionStatus.Closed;
        }

        public static readonly DependencyProperty EntityIDINProperty =
            DependencyProperty.Register("EntityIDIN", typeof(string), typeof(SendMailActivity));

        [CrmInput("Entity ID InpuT")]
        public string EntityIDIN
        {
            get { return (string)GetValue(EntityIDINProperty); }
            set { SetValue(EntityIDINProperty, value); }
        }
    }
}