A simple class that simulates the work of KZPMailClearing.exe The Bulgarian Commission for Consumer Protection requires each email to be checked via their KZPMailClearing.exe, so there is no API or any web solution for that.
kzp.bg does not provide a text file with hashes anymore, so this lib will not work. For more info https://kzp.bg/proverka-na-mnozhestvo-e-adresi