For the ping test, you could not do an actual ping as the email domain server may not have ping switched on for security reasons. If by ping you mean connecting to the senders mail server and checking the email from address, this can be done quite easily. Valid emails such as newsletters may have a no-reply address which is not valid. So a category of false positives is opened up.
ID theft occurs continually, bouncing emails to a stolen address makes the problem worse, especially for the unluck recipient.
By the time your mail server accepts your email address the spammers know they have a valid address. Tackling the problem at the front end is already too late...