Checking a blocked IP using Spamhaus
You can check if an IP address is in one of Spamhaus’ blocklists by going to the following site: https://check.spamhaus.org/check
Type in the IP that you are searching for and click Lookup
If the IP is in one of Spamhaus’ blocklists, it will tell you the reason for the addition.
The following example shows the search results for IP 201.173.168.107.
The following example shows the search results for IP 72.11.23.9.
To search the IP directly using a URL, use the following format, where x.x.x.x is replaced by the IP address to search: https://check.spamhaus.org/listed/?searchterm=x.x.x.x
Note that if the IP is not listed, it will show an error, and you can enter another IP in the search box to check.