All too often we still see automatic notifications along the line of "Oops, you sent one of my users a virus. I've kindly removed it, please clean your PC". These things are a major contribution to the damage that email worms are doing to the Internet, here is why.

The majority of email worms (by now, practically ALL) use fake source addresses. Since the fake address is usually one of the addresses the virus picked up from the PC while looking for email addresses to send itself to, this fake source address is often a valid email address. Two examples of the problems that this causes when automatic notification of senders happens are:

• Here sits Ms X, her anti-virus software properly maintained, no virus on her PC, and suddenly she starts getting emails from email filters telling her she has sent someone (maybe someone she knows) a virus. If she's the average PC user this message is likely to cause considerable concern, as she probably doesn't know that most email worms use fake source addresses. She spends the next couple of minutes or hours scanning her PC for the virus, just to find no virus on her PC. By now she's been given a big fright and lost some work time.
  Now multiply by a couple of hundred thousand and the real problem starts becoming apparent, all those people losing valuable work time scanning for a virus that isn't there.
• Email in general, spam to a great extent and virus email to a growing extent, is a major portion of the load on Internet connections and bandwidth around the world. With automatic sender notification there are now suddenly two email messages involved in each virus infected message; the original virus and the notification. As most of these notifications go to the wrong people, these notifications are a serious waste of limited bandwidth. Again looking at hundreds of thousands of messages per day, this is causing the "Internet experience" to slow down for everyone.

This whole problem can be solved very easily by email server administrators configuring their virus scanning systems differently. Simply turn off notification of senders in the virus scanning portion, if the affected message was actually of some importance the recipient can contact the sender by other means and get the problem resolved. Note that notification to recipients should be left on so people will know if an email destined to them has been stopped because of a virus.