This feature is from another email server vendor.
I found it's quite useful, as most of the time GMail/Outlook.com/hotmail.com IP Only listed in ONE of these RBL blacklist, so if it failed multiple times, say 2, then it's probably a spam IP.
IP from GMail/Outlook.com/hotmail.com normally De-listed themselves quickly as well (within minutes to 1-2 hours), is there a registry key that we can add this # of Matched RBL, then delete directly? or can you please consider adding this feature to the next release?
Honestly, failing just one RBL generate high false positive.