MS-CRM 2013 Invalid Participant Object 9

I want to send an email notification after creating a contact in CRM.

To do this, I wrote the following code ... but it throws an "Invalid member of type 9" type exception. I searched for it but didn’t find any reasonable help

thank

code:

  //Defining Activity Parties (starts)
  Entity Fromparty = new Entity("activityparty");
  Entity Toparty = new Entity("activityparty");

  //set partyid
  Toparty["partyid"] = new EntityReference("contact", ContactGuid.Id);
  Fromparty["partyid"] = new EntityReference("team", ConsumerTeam.Id);

  //create email entity
  Entity Email = new Entity("email");
  Email["from"] = new Entity[] { Fromparty };
  Email["to"] = new Entity[] { Toparty };
  Email["subject"] = "Account Login Information";
  Email["description"] = PopulateBody(UserName,Password);
  Email["directioncode"] = true;
  Email["regardingobjectid"] = new EntityReference("contact", ContactGuid.Id);
  Guid EmailID = Service.Create(Email);

  //Sending email
  SendEmailRequest reqSendEmail = new SendEmailRequest();
  reqSendEmail.EmailId = EmailID;//ID of created mail
  reqSendEmail.TrackingToken = "";
  reqSendEmail.IssueSend = true;
  SendEmailResponse res = (SendEmailResponse)Common.Common.Execute(reqSendEmail);