Suddenly this morning I started receiving “Undeliverable” messages from email servers all around the world, many of them complaining that I’m sending spam, or sending to expired email addresses. The messages were coming in at several per minute, flooding my inbox. In a half hour I had a few hundred.
One’s first thought when this happens might be that perhaps your own computer has been compromised with a trojan, and is sending out spam at a huge rate. But that’s almost never the case. Spammers do compromise innocent computers with trojans, and they do force them to send out spam, but they never use the correct return address.
When email was invented it was primarily for University and Defense Department inter-office communication. It was naively assumed that someone was who they really said they were, and so there were no safeguards against “spoofing”. The spammers and con-artists have taken advantage of this, and send out their messages with bogus return addresses. The return addresses are harvested from various sources; it’s very hard to keep your email address off these lists.
Typically they will use one return address for a day or so on one or a few computers, and then as the spam filters adjust they will move on to another. So I know that if I just sit tight this flood should be over by tomorrow.
But fortunately the compromised email address is one of my “throw-away” addresses that I don’t really need. I create these and use them in cases where the address is likely to be made public.
I disabled that address and like magic the emails stopped.
The computer/internet world is a jungle, with parasites and predators lurking everywhere. Compromised computers can be made to send out millions of spam messages at little or no cost, and if one in a million recipients fall for the scam it is worth it.
