Level 1 policy only contains single IP addresses [ /32], which were used by spammers / abusers. Level 1 includes both automatic and manual listings.
IP's get listed in Level 1 automatically if they either try to deliver e-mails to spamtraps or if they are involved in port scans or probes or any kind of attacks against UCEPROTECTs servers.
Every IP address temporary listed as Level 1 expires automatically 7 days after the last spam email from it hits our SPAMTRAPS.
Is the information on our site wrong or incomplete? You don't want us to monitor your blacklist? Or do you operate a similar blacklist? We would like to hear from you!
We keep some statistics on blacklists. Below is the graph for dnsbl-1.uceprotect.net. We test blacklists by asking them to respond to known IP's that are blacklisted and known IP's that can't be blacklisted. Not every blacklist has such IP's, we test them with what is possible. We keep if we get any response or error messages and the response duration. Lower response times are better. These statistics may be useful for email server administrators to pick which blacklist to use.