There is no such thing as absolute security, so make sure you have regular backups and apply updates early and often. But what if a site you’re responsible for has been hacked? Even after you clean up the damage it’s always a good idea to check to make sure that your site hasn’t been blacklisted.
If your IP address or domain has been blacklisted it could affect your ability to send email and/or appear on the search engine results pages. A quick search will yield dozens of tools that can help you with this. This article should at least help get you get started.
Since a compromised server could have been used to send spam email, distribute malware or host/post webspam it’s worth checking the DNS-based (DNSBL) blacklist providers, as well as search engines.
To check if your mail server has been blacklisted, MXToolbox has a great feature along with many other useful tools for mail troubleshooting.
To check if your website or domain is blacklisted in Google, the following tool should help:
Sites can get blacklisted for a variety of reasons, so if it happens to you all is not lost.