Determine if e-mail message can be successfully sent
c#, email, spam-prevention
Solution
Unless you used images with hashes you track or similar, I don't think you will be able to for security reasons. A lot of mail clients don't automatically download images too.
Imagine if spammers could reliably determine which of their emails were being received?
You could try ping the server... i.e. gmail.com but I don't know how reliable this will be either.
Problem
I am working in a mailing application in C# and, basically, I need to be able to determine which recipients successfully received the message, which ones did not, no matter what was the failure reason. In summary, I need an exception to be thrown whenever the email address does not exist, for example. However, SmtpClient.Send does not throw an exception in this case, so I'd need to monitor the delivery failure replies and parse them, maybe. I know this is not a simple task, so I'd ask you experts some tips on how to handle the main issues with email sending. Thanks in advance!!