For years, I’ve been opposed to email black lists. I think that they unfairly penalize folks who happen to be on the same ISP as soulless spammers. However, this morning, I finally broke down and put blacklist restrictions on my mail servers.
Today I have received perhaps a dozen spam messages, as compared to the 500-600 on a normal day, while at the same time still receiving the normal volume of valid email.
So, I guess consider me a reluctant convert to DNS BLs.