Mail blacklists: How do I know if my IP is on a blacklist?

Mail blacklists are databases that collect suspicious IPs from which bulk mailings are sent, potential spammers. Through them, email providers try to minimise the invasion of our inboxes by junk mail. When sending an email, the email service provider (e.g. Gmail) queries these databases and if it finds the sender on one of these blacklists it prevents the message from reaching the inbox.
If we do not follow some key standards for deliverabilityt is sometimes very difficult to get out of a blacklist of campaigns.
There are many websites where you can check if your IP has been included in a mailing list. One option is to ask on the website of each blacklist, but in this post we will talk about other more generic websites, where all the blacklists are checked in search of possible penalisation. Here are some tools you can use:
Multirbl.valli.org 
Mx Tool Box
What is my IP adress
Blacklist Master
DNS BL