What was that about$%: Three messages in a row from people I had never heard of asking me to stop spamming them amidst the usual pile of spam. I never sent any spam messages. Or did I$%:
Unfortunately it is quite possible, even quite easy, to fake the sender of a message. While the simple techniques will not fool a serious inquiry, they can certainly make it look at first glance as if it is you that is sending out these spam messages by the hundred. It's a rather annoying variation of a "Joe Job Attack". This is, if you like, Joe Job Spamming, and it works as follows:
Regular spammers build up a massive list of email addresses and spam them at will. The derivative of this is not only to use these addresses in the to: line, but also in the from: line. It's like 2 for the price of one spam. If the address is incorrect or invalid it bounces back to another spam attack address, often with the initial message intact.
So, what can be done to stop this form of spam$%: There's really not a huge amount that can be done inside the current framework. What IS required is an overhaul of the framework. Without getting into a complete history of email it started with companies/universities being able to use an internal messaging system. In these environments abuse was rare and usually easily located. For convenience sake these institutes started linking their systems so you could send email not only to your colleagues at the same location as you, but to nationwide branches also. Like the internet, email protocols grew out of a number of smaller nets linking together. It was not so much designed, as it happened.
Perhaps it is time to overhaul the system completely. One thing is certain and that is that the ability to send e-mail anonymously has a single benefactor - and that is spammers. If we want to get serious in fighting spam - we must remove the ability to anonymously send email.