[ShadowAce]

Spam Spam Spam Spam Spam Spam Ping

[KoRn]

Every company should host their own DNS servers anyway. Not clearly stated by the article, is that an email firewall will do reverse DNS lookups on incoming messages to verify they are coming from where they claim they are in the message header.

If the reverse lookup goes unresolved the message is rejected. I've seen spammers change their domains as much as 4 times per day attempting to prevent being blacklisted by our firewall/filter.

Our company gets about 5,000 emails per day and about 2,700 of them are dropped because they are either spam or contain viri. I sometimes run a tail -f on the maillog file to watch them die in real time lol.