I would like to know if this is possible to ask a SMTP Server if it received a specific email even if I'm not the server who sends the email ?
for instance, user a@sender.com is sending an email to b@receiver.com, then I have an independent server who is asking SMTP Server receiver.com if this email has been received (using Message-ID header value for instance)
I've seen that most of SMTP Servers are implementing DSN, but I don't know if it can be asked by anybody....