Blocklist.de lists IP addresses reported by a network of fail2ban-style sensors for attacks such as SSH, mail and web brute-forcing. A listing here very often means a host has been compromised or is misconfigured, so securing the server is the essential first step.
Why an IP gets listed on Blocklist.de
Blocklists add an IP when they see evidence of spam or abuse from it: mail hitting spam traps, a compromised server sending on behalf of a botnet, an open relay or proxy, or a sudden spike in unsolicited mail. Shared hosting and cloud IPs can also inherit a bad reputation from a previous tenant. It is used by a substantial number of mail servers, so a listing can measurably reduce delivery to those systems.
How to delist from Blocklist.de
Blocklist.de expires listings automatically once the spam stops, so the priority is to find and fix the source, a compromised account, a misconfigured server or a bad mailing. Most senders then clear within a day or two; a manual removal request can also help:
Delisting only sticks if the root cause is fixed first. Run the full Mail Health Report to catch the SPF, DKIM, DMARC or reverse-DNS problems that often cause listings.
Frequently asked questions
How do I check if my IP is on Blocklist.de?
Enter your mail server's IP address (or your domain) in the checker above. It queries Blocklist.de live and tells you immediately whether the IP is listed, along with how many other blocklists list it.
How long does it take to get delisted from Blocklist.de?
Blocklist.de removes entries automatically after a spam-free period - usually a day or two - once the source of the problem is fixed. A manual removal request can sometimes speed this up.
Will a Blocklist.de listing stop my email being delivered?
It is used by a substantial number of mail servers, so a listing can measurably reduce delivery to those systems.