SPAM Blocking

In order to minimize the amount of SPAM recieved at Deep Eddy, we use a perl script called tms originally written by Thomas Erskine and then modified locally. Tms generates custom From: and envelope senders for all outgoing email. It requires the use of qmail to process the various addresses which may be generated. There are four modes that tms may work in, and they are selected based on the address that the outgoing mail is being sent to: bare Our sender's address is unmodified by tms. dated Our sender's address is suffixed to create an address which will expire after a period of time. sender Our sender's address is suffixed to create an address which can only be replied to from the particular address we've sent the message to. extension Our sender's address is suffixed with a particular extension. As configured at Deep Eddy, outgoing mail is sent by default in "dated" mode so addresses can be replied to by anybody for two weeks, and once that time has passed, any mail to them will bounce. Mail to various clients and to lists on which we are active is sent in "extension" mode. When mail is sent to that address, it is automatically put in an appropriate mailbox. If one of these addresses should become a SPAM target, we change the address and bounce anything sent to the old address. Initially we were using the "sender" mode considerably, but found that it was much more work than it was worth. It required our correspondents to learn or store very unwieldy addresses, so we've changed most of those to simple extensions. It turns out that the hand management of the extensions is less work than the automatic management of the "sender" mode addresses. Given that we were already sorting our incoming email into various boxes, this turns out to not be nearly as "high maintenance" as you might expect. Last modified: July 27, 1998