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Blacklist Checker
Check whether the IP address of your mail server is on a well-known blacklist.
Analysis messages from the checker are currently in Dutch.
How does it work?
Blacklists (DNSBL) collect IP addresses that send spam. If your mail server is on one, mail can be rejected or land in spam. We check a range of well-known lists.
Frequently asked questions
What do I do if I am listed?
First find the cause, such as a hacked account or open relay, then request removal from the list.
Which IP should I enter?
The outgoing IP of your mail server. With Microsoft 365, Microsoft manages that.
Does an empty result mean all is well?
It means the IP is not on these lists. DMARC, SPF and DKIM must also be right for good delivery.
Need help with your email security?
We set up DMARC, SPF, DKIM and MTA-STS for you and keep an eye on it, as part of Security and Monitoring.