DNS Blacklist Checker
Check if an email's mail server IP is listed on major DNS blacklists (Spamhaus, SpamCop, Barracuda) that affect deliverability.
What Are DNS Blacklists?
DNS Blacklists (DNSBLs), also known as Real-time Blackhole Lists (RBLs), are databases of IP addresses known to be associated with spam. Major email providers and spam filters consult these lists when deciding whether to accept or reject incoming email.
When a mail server's IP address appears on a blacklist, emails sent from it are more likely to be rejected or filtered to spam. Our tool checks the IP address of a domain's primary mail server against three major blacklists: Spamhaus ZEN, SpamCop, and Barracuda Central.
Being listed on even one blacklist can significantly reduce your email deliverability, making blacklist monitoring an essential part of email infrastructure management.
Why Check for Blacklisting?
For email senders, discovering your mail server is blacklisted explains sudden drops in deliverability. For email list validators, checking whether a recipient's mail server is blacklisted helps assess the overall health of that email address — a blacklisted server suggests the domain may be associated with spam.
Shared hosting environments are particularly susceptible to blacklisting. If another user on the same mail server sends spam, the entire IP can be blacklisted, affecting all domains hosted there.
Frequently Asked Questions
What do I do if my server is blacklisted?
Each blacklist has its own delisting process. Generally, you need to identify and fix the spam issue (compromised account, open relay, etc.), then submit a delisting request through the blacklist provider's website. Spamhaus, SpamCop, and Barracuda all have online delisting forms.
How quickly can I get delisted?
It varies. SpamCop listings often expire automatically within 24-48 hours. Spamhaus requires manual delisting and may take longer. Barracuda processes requests within 12 hours. During this time, your email deliverability will be impacted.
Does blacklisting affect receiving email?
No, blacklists only affect outbound email. A blacklisted server can still receive email normally. However, if you're evaluating an email address, a blacklisted mail server suggests the domain's sending reputation is poor.