Here's something that is probably quite rare for most people, but I came across it today so thought I'd share the info.

Addresses ending in 127 (for example my virgin media address of 86.23.49.127) will fail spamhaus checking.

If an IP address is found on spamhaus then the return code will almost always be 127.0.0.x or 127.0.x.x

However, if not found, it returns the reverse of the queried IP, i.e. in the example above it would return 127.49.23.86

As the PHP script just checks the first value in the array, $result[0], to see if it is 127, then any address ending in 127 will fail, or at least seem to fail.

To get around this I altered the script on my server to check for $result[0] . $result[1] and matched it on 1270 instead of just 127, and it works fine.

I hope that's straight forward enough and hope it helps you if you come across the same situation!

Thanks for pointing this out. I have checked, and in 1.3.0 it does have flawed logic testing for Spamhaus (which will only be apparent from particular IPs).

This problem isn't present in RV2.

As this is a bug, I will update the code to remove this problem and release 1.3.1 shortly.

I have now uploaded 1.3.1 which incorporates a proper fix for the Spamhaus issue. There will not be any false positives anymore as the DNS lookup is checked for a valid response first of all (if not listed, Spamhaus will NOT return a result). Only if there is a valid response is it analysed (this is similar to the method used in RV2).

Sorry for the bug, and thanks for letting me know so that I could get a fix done.

Thanks for your quick help with this!