My spamblocker sends messages from unauthorised senders to a ‘suspect email’ folder and sends the sender a message describing how to request authorisation. The message may be modified by me. What if I copied an ‘undelieverable e-mail’ response into my outgoing message – pretending I don’t exist, as it were? Would that get me off of the lists?
I doubt that many spammers care about whether the addresses they’re sending to are valid. They are just counting on the tiny fraction of respondents who actually respond to the offer. Sometimes the reply-to address in spam isn’t even a valid one.
It might get you more spam.
Some of the e-mail address harvesters will send out messages to every address it can find, looking for the receiver to either open the e-mail or respond to it. If that happens, you get put on the list of having an active e-mail account. That list then gets sold to a spammer, who blasts a message to everyone on the list. Once you are on the list, no message you send back can get you off of it.
Any reply that comes from you is going to alert the spammers that they’ve hit a live email address, whatever the contents of the message, and therefore get you more spam.
Of course, since almost all spam has faked return addresses, CAN-SPAM notwithstanding, your “reply” will probably just bounce anyway.
Nevertheless, if you really want to do this, there are programs that will simulate your address being invalid - “bouncing” the email back to the sender. I believe Mailwasher can do this, but it’s not free.
Or contribute to the DOS attack going on in the inbox of the poor schlep who’s legitimate address was forged as a from: address by the spammer.
Or forged as the return path…