Abstract mail service.
public interface ISmtpService
{
/// <summary>
/// Sends the specified message to an SMTP server for delivery.
/// </summary>
Task<SmtpResult> SendAsync(MailMessage message);
/// <summary>
/// Create a default email message
/// </summary>
/// <returns>MailMessage</returns>
/// <remarks>
///Central definition capability: To, Cc, Bcc, IsBodyHtml, Subject prefix
/// </remarks>
MailMessage CreateDefaultMessage();
}