What Is an IP Blacklist?
An IP blacklist (also called DNSBL or RBL) is a database of IP addresses that have been flagged for sending spam, hosting malware, participating in botnets, or other malicious activities. Email servers, firewalls, and security systems check incoming connections against these lists to block suspicious traffic. Being blacklisted can prevent your emails from being delivered and may block access to certain websites and services.
What to Do If Your IP Is Blacklisted
- Identify the cause: Check if your machine is infected with malware or if your email server has been compromised.
- Fix the issue: Remove malware, secure your server, and stop any spam activity originating from your IP.
- Request delisting: Most blacklists have a delisting process. Visit the blacklist website and follow their removal instructions.
- Contact your ISP: If you're on a shared IP, your ISP may need to reassign you a clean address.
- Monitor regularly: Set up alerts to catch future listings early, before they impact your email deliverability.