We all get annoyed by spam, and by those infected emails sent by viruses. But over the past weeks and months, I found this annoyance to be getting minor compared to another one.

Spam mails can filtered out by spam filters, viruses can easily be filtered out by virus filters. But more and more webmasters apply either file extension filters or antivirus filters that bounce back infected emails. Now instead of having one bad email, we've got a second in circulation that is putting double the strain on the Internet infrastructure. And my question is: why?

Anti-virus companies spend a huge amount of time and effort on researching viruses. They know exactly which virus is using spoofed sender addresses and which not - hey, they even know if the viruses chooses those spoofed addresses from the address book, from cached Internet paches or from wherever. So why does their antivirus mail gateway software bounce emails, telling some totally unrelated person "you sent a virus infected email, and product XY cleaned it", if they perfectly know that the virus was not coming from that person?

I see only two possible reasons:

• In some places, law restricts administrators from having machines delete or even read emails. In those cases, the administrators need to get the consent of the users to even apply a spam filter. Well, in that case they can get the consent to delete virus emails as well.
• It is a great advertisement for anti-virus companies to have their mail gateway scanning software send those replies. Computer rookies will actually get fooled by that and already accidently know which software cleans this specific viruses. Advanced users will only give the hassle to delete the email after reading this advertisement.

There are two laws coming into my mind. One is the law against improper competition (called UWG here in Germany), and if you regard these replies as advertisement (as they are really not necessary), that's exactly what it is.
The other one is called computer sabotage. As every mail administrator can set up his own reply message and the content of the mail differs from spam, those are much more difficult to catch through a spam filter, and clog your inbox. And filling my inbox with useless bounce emails so that it takes me hours to clean it up is exactly that - computer sabotage.

So why do I write this? Because if I would do the same as those administrators - set up an effective bounce against all mails I don't like, even if I know the sender is not responsible - that would create an endless loop of mails sends forth and back, and because in all of our inboxes, this is getting a worse problem than spam and viruses themselves. I already wrote a small article about that in our articles section, but I wanted to bring this to everyones attention through the news as well, in the hope that some postmasters will improve their bounce strategies and that some poeple will complain to AV companies about their softwares ugly kind of advertisement.

Otherwise all these current discussions about anti-spam standards are useless, as the majority of spam in the future will be coming from legit postmasters of legit networks who are only bouncing back bad emails.