|Subject||:||Please do not bounce SPAM|
|Date||:||12 Dec, 2006 on 00:35|
|Going only by the description in the recent announcement of the release of SpamCopy in Software News:
Those of you who already know why this is wrong don't need to read this post. To everyone else, please do not use this program to send bounces of your spam!
Firstly do you really imagine the diligent spammer trying to conserve time by reading all the bounces he might receive from the millions of mails he sends out by automated processes, to find the "invalid" emails and carefully delete them from his list?
Secondly and more importantly, the person who sends spam cannot be identified from the emails you receive. That's right, the address in the "From:" line of the email, and any Sender found in the headers, is just made up. Usually chosen at random from the list of victims receiving that batch. So if every recipient of a particular spam sends a bounce, the poor sap blamed for it will receive hundreds or thousands of bounces. In fact many misconfigured ISP's bounce spam, and clobber other servers with it. It is called backscatter, it's a huge problem, and it is considered abuse.
There are two cases when this might not be true. The first is the Nigerian scammers who claim to have a hidden fortune they want your help laundering, so you need to send them your bank information and some money. They send their email from free webmail accounts, which often don't let them fake their From address. But usually this abuse gets caught pretty quickly and the account gets closed. This is why they give you a different Reply-to address. I've been told the return mail is actually handled by a different person, so the sender probably isn't the one who will read your bounce and let the other Nigerian diplomats know not to use your address anymore.
The second case is those newsletters you signed up for at 3am while you were shopping for new slippers and absent-mindedly filled in your email address and didn't uncheck the box that says "Please send me advertisements." These are usually not spam, and have mechanisms for unsubscribing you. A bounce will be received, but it is highly unlikely the receiving server processes it to find your address. More likely it just deletes it and moves on to accept the next one, and all the other spam it receives. When these are legit, it is much more reliable to actually use the provided web link or special account to unsubscribe. When they are not legit, you definitely do not want to follow any of their web links.
If you do send bounces, usually you are sending them from your ISP's SMTP server, and depending where you send it you could get it listed in one of the myriad abuse blacklists. Probably not if it is a large ISP, but usually then your authentication is recorded in the mail headers, so you are identifying yourself and your address to some unknown recipient, and do you really want to do that?
I haven't looked at this program yet. It may be very useful for some things. But bouncing SPAM is a real bad idea. If its author reads this, I would encourage him to get in touch with me privately if he wants to and I can try to help work out a better answer.