[German for tar pit] A trap set to punish spammers who use an address harvester; a mail server deliberately set up to be really, really slow. To activate it, scatter addresses that look like users on the teergrube's host in places where the address harvester will be trolling (one popular way is to embed the fake address in a Usenet sig block next to a human-readable warning not to send mail to it). The address harvester will dutifully collect the address. When the spammer tries to mailbomb it, his mailer will get stuck.