Tempfailing for spam -- where does it lead
Submitted by brad on Fri, 2007-01-26 16:27One growing technique for use in anti-spam involves finding ways to "fail" on initial contacts for sending mail. Real, standard conformant mail programs try again in various ways, but spammers, in writing their mail blasters, tend to just have them skip that address and go to the next one in their list.
Two common approaches include simply returning a "temporarily unavailable" status on any initial mail attempt that might be spam. Another approach is to have dead MX records both at the "try first" and "try last" end of the MX chain.