Cloud DNS: <key>.noip.mail-beta.abusix.zone.
Rsync File: beta-lists/noip.zone
Return Codes: 127.0.0.100
Test Points: 127.0.0.2, 127.0.0.100
Listing duration: 25 hours
This list is built by storing every IP address we have seen sending SMTP traffic to our traps or to our partners over the last 30 days. Any new IPs found that have not been seen are then listed for 25 hours.
Being listed doesn't necessarily mean that the IP address is bad, but this is useful for scoring and meta rules.