Did you know that if a spammer uses your email address as the FROM: address, which is easy to do, all the bounce messages will go to your email address? If the spammer really hates you, they will send millions of emails with your FROM: address and you will get a million bounce messages.

Can you stop this or prevent this? No

Why would a mail provider send you a bounce message, knowing you’re innocent? Because that’s how someone wrote the protocol back then, and nobody changes it or does it differently because … reasons.

Does the spammer get a bounce message? Nope, not one.

Does the SMTP sending account owner whose credentials were stolen be notified about bounces so they can stop the spam? Nope.

Just millions of emails sent every day to poor schlameels who have no idea why they are getting them and who can’t do anything about them.

The more I learn about the email protocols, the more I realize how terrible the design is.

#emailsecurity #spoofing #cybersecurity #spam

  • ExperimentalGuy@programming.dev
    2·
    2 days ago

    I haven’t looked into email in a while, but I’m pretty sure this is like saying TCP is insecure. Like yeah, if you communicate using plaintext over TCP you are vulnerable but most out of the box solutions nowadays don’t even function that way. You’d have to go write your own application that communicates using plaintext over TCP.

    In the same vein, the boxes out there that just run SMTP without any security would be the same way, but most boxes won’t be susceptible to this attack because very few people are running just SMTP.

    Disclaimer: I have not read up on SMTP in awhile but iirc, SMTP works with very little verification and is very susceptible to a lot of different attacks by itself.