Something happened when I was sending a newsletter recently... the test messages were not arriving at their destinations as they normally would. After a little research, I discovered my IP address had been blacklisted as a spam source, and my test mails were being returned.
A machine behind the firewall been compromised and was participating in a botnet - it has since been fixed.
I found a useful web site that reports the lists where my IP address existed as a spam source. The site is
My IP (whatismyipaddress.com) It appears to have other IP tools and related articles that might be useful.
I previously used dnsstuff.com to do these lookups, however they require a membership now (free) and it's just one more user/pass I need to remember. No user/pass is faster.
According to the lists my IP address has been blacklisted on, the record should expire from between 3 and 7 days. Some lists offered removal requests, which I took advantage of, some even offered immediate removal for a fee. I will not be sending a message to my list subscribers until this blows over because changing will be a huge hassle.
