IP addresses that have a low trust factor are often included in databases commonly known as blacklists. Unfortunately, most of these databases provide inaccurate information about IPs. For instance, you can easily find your own IP address in a blacklist. Besides that, blacklists retrieve information from various IP databases which may lead to a misconception about a particular proxy provider.
The only way to find out how often a blacklist is updated is to contact the publisher directly. We assure you that even if you find an IP address in a blacklist, it will not affect your performance in any way.
SOAX uses the MaxMind IP database, which is why we suggest referring to our own checker in order to identify IP addresses.