We have an application that is running on a SharePoint 2010 server that sends an email. We (the sender) want to receive delivery notifications but we are unable to retrieve them on the live system.
I've set the System.Net.Mail.DeliveryNotificationOptions to OnSuccess | OnFailure | Delay and it is running fine on our internal test system. I receive the notifications in my inbox (which is the "from address" that I used). Internally we use Exchange 2007.
At the customer site with the same solution no notifications are received. They don't use Exchange for the email delivery from SharePoint but some other SMTP server.
Can it be that the delivery notificaiton option only works with MS Exchange? Or does it use a standard (well, it's Microsoft) that other mail servers also understand? The documentation doesn't mention any mail server requirements.
Could you try adding a "Return-Receipt-To" address in case the mail server in use at the customer site requires it?
AFAIK, the .Net.Mail is using standard SMTP calls but not all SMTP servers are created equally....
来源：https://stackoverflow.com/questions/8800299/does-system-net-mail-deliverynotificationoptions-only-work-with-exchange