So, you've experienced the great frustration of finding your email rejected by one or more customers due to some blacklisting organization. Assuming that you've already read our article on "basic information about blacklists," here's what you need to do.
First, you need to confirm that this is the reason for your email being rejected. Look carefully at the notice attached to the email that was rejected. It should specifically indicate that your email was rejected by a particular organization or company, and give some basic information on what you can do to get off the blacklist. Information on getting off the most common blacklists is provided or linked to below. For others, use our lookup list of blacklisting organizations to find the link for the one that has blacklisted your address. Note that if you are using a shared server provided by a web hosting service, then you may need to ask your hosting provider to address this issue for you. Also note that most blacklists are blocking IP addresses, not domain names, etc., so if you are sharing an IP address with other users, your best bet in the end may be to get a new IP address that is significantly different (in a different Class C block) than the one that was blocked.
SORBS: You may have a fine to pay to get off this one.
Check out this page: http://www.us.sorbs.net/overview.shtml to see if you need to pay the fine.
The form for delisting is here: http://www.us.sorbs.net/cgi-bin/support. Delisting with SORBS is usually fast (less than one day).
COMCAST: This one is usually pretty easy and quick to get off initially, but if there is something triggering a recurring entry in their blacklist, you may have great difficulty staying off the list, and may do better to move your site to an address that isn't blacklisted (assuming that your email isn't what's causing the blacklisting!). Go to the Comcast RBL removal request submissions form at http://www.comcastsupport.com/rbl to request delisting.
AOL: AOL has created a system where you can actually reach a live operator for help! Go to http://postmaster.info.aol.com/ and follow their instructions.
VERIZON: Go to http://www2.verizon.net/micro/whitelist and complete the form for whitelisting of your address and domain.
Need more information? Click on the following link for more detailed information on issues and solutions surrounding email delivery.