task.cs

public class Task : ActiveRecord
{
  public string Name { get; set; }
  public int AssignedTo_UserId { get; set; }
  public DateTime DueOn { get; set; }
  
  public Task()
  {
    DueOn = DateTime.Now.AddDays(1);
  }

  override void AfterInsert()
  {
    Email.Send(AssignedTo_UserId, "New Task", "You have been assigned a new task");
  }
}