Email confirmation?

This is not possible because the SMTP protocol does not guarantee e-mail delivery. See this link for more explanation.

It is not possible to know for sure if someone received or read an email, but a simple alternative is to link to the actual message, so you can check whether the link has been accessed or not.

As others have said before, the SMTP protocol does not guarantee that the message will be delivered, nor that the Email Client will send a notification that the message has been received.

However, some Email clients (such as Outlook or Thunderbird ) are able to interpret Head Disposition-Notification-To and send a notification.

public void PrepararNotificacoes(ref MailMessage mensagem)
{
    mensagem.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure | DeliveryNotificationOptions.OnSuccess | DeliveryNotificationOptions.Delay;
    mensagem.Headers.Add("Disposition-Notification-To", "[email protected]");
}

In this case the notification will not be sent to a URL, but to an email, and even if the email is received, there is no guarantee that the notification email will be sent or that it will arrive at the destination.

As an alternative to automate this process, you can create a POP3 service that receives notification emails, this service can write to your Bank, create a WCF Client, etc ... this way you could register that the email was read .

Yes has it. Using the tool Mautic .

Mautic is a marketing automation tool, it has a functionality that would suit you what would be sending email to a list of customers. When you send emails with mautic, you can know the exact time that the customer received and when it opened.

With this tool you can make marketing campaigns among other things. And the best is Open source and free.

The only downside is that the documentation only has English. But there's the Facebook community that may be helping you.