I've been Exchange Administrator for a longer part of my IT life. As any mail admin (not just Microsoft Exchange) will tell you having your SMTP server on one of the blacklists is not fun. While generally useful DNSBL blacklists for normally functioning SMTP servers are pain. That's why it's advised to proactively monitor your IP addresses and see if/when they are blacklisted so you can react (either by changing your SMTP IP Address or by trying to remove the IP address from the blacklists). While there are many options on out there (my favorite MxToolbox.com included) I needed something more configurable and free. So here it is…