If you're a badly humor-impaired or particularly clueless spammer
Thou shalt not spam!
The Motto of Unit 9377 of The Lumber Cartel, AKA "The Birk
Death"
It's rare that people know about this commandment, yet is in my opinion one of the most important ones - do never, ever send unsolicited commercial email or crap that is dangerous to Windows users. Do never send to any alphanet.ch or snoop.alphanet.ch denizens any unsolicited commercial email. Do not even think about it. I'm rather good at unmunging SMTP headers and then striking back by reporting you either to your ISP or upstream provider, or to SPEWS and other DNS blacklists. Which basically means you won't spam this domain after I've done this. Or maybe, you can get into touch with Cabal Network Security, which is sure to be very beneficial for your health, at least to the point that paying your health insurance primes after the visit (tinv) will be pretty pointless.
Far too many servers on the internet abet such abuse by having their mail relays wide open, or have their proxies wide open to the internet, which will lead to abuses. A modern mail server like sendmail will not relay by default. Neither does Exchange 5.5 or 2000. With 5.0, you're bascially forced to upgrade. A good alternative would be PostFix, but there are other MTAs that will prevent unsecured relaying.
If you happen to have users that abuse your MTA by sending unsolicited commercial email, remove them from your network as fast as possible. They won't be a boon to your business or reputation. Sometimes, you can educate them, but that's pretty rare. Lots of hosting companies found out that a listing in SPEWS can be pretty permanent and effective to reduce the number of spam emails received by normal internet users, including the author of this page.
At any rate, we're fed up and started tracking down spammers long ago. We take considerable time to introduce spam-filtering measures. We use content blocking. This is helpful, but not decisive since we still get spam, even from outlets situated in Switzerland
like New Horizons Business Corporation, behind which no one else than the Spammus Maximus Martin Fürst is hiding, a well-known long-standing spam operation in Switzerland. If the "telemarketing lightning" struck some buildings in the vicinity of Zurich because of bad karma from their occupants, I'm pretty sure the amount of voice recognition software, sex toys, Helly Hansen jackets and overpriced digital cameras sold in Switzerland would not really decrease.
And this are our tools to hunt them:
 The classical Luser Attitude Readjustment Tool |

This lucky soul just recovered a projectile that was used by Unit 80 of The Lumber Cartel to make sure a spammer won't perpetrate his dirty deed again | |

American Agents of the Internet Cabal like little flimsy plastic rifles |  We European Lumber Cartel Units prefer more compact rifles. It's not called the Evil Green Rifle (tanegr) for nothing, as our long list of exterminated
spammers can attest. | |
Rest assured that we (tinw) will post more pictures
Also read the sensible column from William R. James (wrjames lives at spamreaper punkt org), Thanks the Spammers! about spammers and their effects on the internet.