How to Remove Your Website from a Blacklist
Your domain name or IP address domain is blacklisted when it has been found to send out spam e-mail. If your site has been blacklisted, it may not be your fault — especially if you're on a shared server. It may be that another site on the server has been purposefully sending spam.
It's also possible that your site, or another site on a shared server, has been hijacked and used for sending spam.
If you are on a shared server, inform your host that the server has been blacklisted and ask your host to investigate. Your host will normally be able to get your site unblacklisted within 24 hours. The host will first check to find out which site has been causing the blacklisting.
If your site is the culprit, the host may take it offline until you can get a security expert to fix whatever is causing the problem.
If your server is a VPS or dedicated server, however, check with your web host. Your host may well say that cleaning the problem and repairing the damage done is your responsibility because it's your private server.
In this case, the quickest and easiest way to fix the problem is to hire a security consultant to clean up your website and prevent the issues from happening again. The consultant is normally willing to contact the blacklisting agency and provide the details that are needed to unblock the site.
You can also contact the blacklisting agency yourself by going to its website and completing a form to remove a site from being blacklisted. Make sure that you have fixed any issue first because blacklisting agencies do not take kindly to whitelisting servers that are then very quickly blacklisted again because the issue still exists.