A listing by Suomispam Reputation indicates that the affected IP address has been deemed suspicious and/or a source of spam. If the IP address has a reputation of sending spam or has been previously blacklisted by Suomispam, the IP address will likely be blacklisted at the first indication of spam being sent.
Suomispam Reputation Reports Sources Of Spam
Spam-based Blacklists are those that will list either single IP Addresses or entire ranges that have actually received Spam, i.e. Unsolicited Bulk Email (UBE) in their Spamtraps from an IP-Address. This could be a result of a compromised email account, an Open Relay, or simply sending mass emails / marketing and not following best practices according to the "CAN-SPAM Act of 2003" (ref: https://en.wikipedia.org/wiki/CAN-SPAM_Act_of_2003)