Woody's SMTP Blacklist IPv4 identified this IP address or domain as sending spam.
This could be because of a virus, bad software, or misconfigured mail server. Woody's SMTP Blacklist IPv4 thinks spam senders should be stopped, but safe IPs and domains should be allowed.
You can learn more about Woody's SMTP Blacklist IPv4 delisting by visiting their website: https://blacklist.woody.ch/