I am wondering how I can find out who is spamming and how to stop the problem. Someone recently got my server ip banned from roadrunner so I cant send email to anyone on roadrunner. Any help would be appreciated.

its usually insecure scripts on the server that spammers use. they exploit these scripts and inject what they want to send and who they want to send it to. You really need to check your access log files as well as your mail log files.

You also need to provide more information, what control panel (if any) do you run and what MTA (mail server) do you run? It may also help to look at one of the spam'ed email's headers.

I'm sure you can also contact roadrunner and they will be willing to let you know why you got blacklisted from their network.