I have dozens of WordPress sites on a CentOS 6.4 server, all operating through one IP address, and it turns out that that IP has just been blacklisted because the server has been generating spam.
This is a two part question:
1. How do I locate the source of the spam?
2. What can I do in the future to catch this type of thing before I get blacklisted?
Thank you all in advance for any help you can offer in this area.