Being blacklisted can be a major source of trouble, especially if you have been blocked by a major provider, such as Gmail or Yahoo.
It is your own and exclusive responsibility to keep your IP clean.
While you can request details from providers that have blacklisted you, they may not always provide them.
Before requesting that you are removed from a blacklist, be sure that you have resolved any problems that could have led to your being blocked or you’ll end up blacklisted again.
Once you are certain that you have dealt with any potential issues, you may be automatically removed from a blacklist after a week or two or you may need to contact the postmaster for the domain that blocked you.