Your IP has been blocked because it is blacklisted. For details please see http://www.spamcannibal.org.
An entry on the blacklist may have several reasons:
1. You are a well-known spammer.
2. Last time a well-known spammer was using the dynamic IP address which you got from your ISP (Internet Service Provider), your e-mail address or the username you have choosen.
3. Your ISP is well-known for a lot of spamming customers and is not fighting against spammers enough.