Email Blacklist Checker

A blacklist listing can cause receiving mail servers to reject your email outright, deliver it to spam, or apply additional filtering. The severity depends on which blacklist you are on. Spamhaus listings affect delivery to virtually all major providers. Barracuda listings primarily affect enterprise environments. SpamCop listings are more temporary and less severe.

Common causes include: sending spam or unsolicited bulk email, high spam complaint rates, operating an open mail relay, being a compromised machine sending malware or spam, having your IP in a known dynamic IP range (like residential broadband), or sending to many invalid email addresses that trigger spam traps.

It depends on the blacklist. SpamCop listings expire automatically within 24 hours of clean behavior. Spamhaus listings remain until you address the root cause and request removal. Barracuda and SORBS require manual delisting requests. Some blacklists expire after a set period regardless.

Yes. A compromised server or account on your IP can generate spam without your knowledge. Shared IP addresses on email service providers mean other users' behavior can affect your delivery. Spam traps — email addresses maintained to catch spam — can appear in purchased or scraped lists and trigger listings when contacted.

Spam traps are email addresses maintained specifically to identify spammers — they never sign up for email and only receive mail from people who scraped or bought lists. Hitting a spam trap is a serious signal to blacklists. Avoid spam traps by only sending to people who explicitly signed up, verifying addresses before adding them to your list, and removing inactive subscribers regularly.

Check both. Your sending IP address is what most DNSBLs track. Your domain may also be listed in reputation databases if it has been used in spam or phishing. If you use an email service provider and share their IP pool, check the specific IP addresses your ESP uses for your sends — find these in your email headers.