Blacklist check: is your email being blocked?
Enter a domain or IP address. We find your mail and web server addresses and check them, plus the domain itself, against widely used DNS blocklists.
- Free, no sign-up
- Results in seconds
- Public data only
Three steps, a few seconds.
We find your IPs
From your MX and A records, or the IP you enter.
We query each blocklist
Each list is checked over DNS. Lists that refuse automated queries are shown as u0022not checkedu0022 rather than clean.
Fix and delist
If you're listed, find the cause first (a compromised account or device), then use the delisting link.
Why would my server be blacklisted?
Usually a compromised mailbox or device sending spam, a misconfigured server, or a shared IP that another customer abused.
I use Microsoft 365 or Google Workspace. Does this matter?
Their IPs are shared and managed by the provider. A listing there is rarely yours to fix, but your domain can still be listed on domain reputation lists.
Why isn't Spamhaus shown?
Spamhaus doesn't allow commercial lookups through public resolvers without a data query key. Your administrator can add one in the Toolbox settings.
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Want an expert to look at your results?
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Tell us about your IT.
We answer almost every inquiry within one business day.