[0xFluegel]

I can see how that happens immediatly...

    var domain = addr.split(['@','.']).take_last(2)
    var tld = domain[1]
    // check TLD against wacky rules...

See, boss, it's easy. What's next?

[snet0]

It's also possibly just some arcane regex incantation that someone implemented 12 years ago and nobody has been able to decipher it since.