Bob Beck wrote: > No. DNS based whitelisting does not belong in there. because it is > slow and DOS'able > > spamd is designed to be high speed low drag. If you want to do a DNS > based whitelist, write a little co-thing that spits one into a file or > into your nospamd table that then spamd *does not even see*. > > In short *spamd* is the wrong place to do this. put your dns based > whitelist in a table periodically
This sounds like a potentially problematic approach. There are now spam networks that circumvent DNS blacklists, even if the SMTP server queries for each domain it receives. The best I can tell, they do this by burning through domains on cheap TLDs like .xyz. Locally caching DNS blacklist responses seems like it could magnify this problem substantially.
