Adding RBLs to sendmail

[A. Eijkhoudt]

Scott Silva wrote:
> There was a list that went down several years ago, whose name escapes 
> me, but instead of turning off their servers, they returned every lookup 
> as if on their list. That one caused a lot of problems. Every message 
> got marked as spam.

Indeed, a reasonable list of dead DNSBLs can be found here: 
http://spamlinks.net/filter-dnsbl-dead.htm

It's a nice site; it also lists many working DNSBLs, instructions, tips...