Bounce address

A bounce address is like a pretend return address for email. When you send an email, it has an address where it came from, sort of like a return address on an envelope. Sometimes, the email can't be delivered - maybe the address is wrong or there's a problem with the email server. When that happens, the email gets sent back to the return address, which is called the bounce address. It's like when you send a letter to Santa Claus, but the elves can't find him, so they send it back to you. The bounce address is important because it helps keep track of which emails got sent back and why.