private EMailRM CreateEMailForContact(Commands.V1.Contact.EMail.CreateForContact cmd)
        {
            EMail eMail = EMail.CreateForContact(_emails++, EMailAddress.Create(cmd.EMailAddress), cmd.IsPrimary,
                                                 cmd.ContactId);

            if (_repository.EMailExistsForContact(eMail, cmd.ContactId))
            {
                throw new InvalidOperationException($"EMail already exists for Contact {cmd.ContactId}");
            }

            _repository.AddEMailForContact(eMail, cmd.ContactId);

            return(Conversions.GetEMailRM(eMail));
        }