posted 3 weeks ago
Do a web search on the terms "check email blacklist". you will find a number of sites that can check the various public blacklists.
Note that organizations and people may have their own black/spam lists as well, and unfortunately, the only way to check against them is to send something to them and have them check their mail logs.
It's quite possible to accidentally get blacklisted - it has happened to me. In fact, Google actually spam-listed mail from myself to myself! But there are generally ways to get removed from such lists if it's a genuine error.
Some people, when well-known sources tell them that fire will burn them, don't put their hands in the fire.
Some people, being skeptical, will put their hands in the fire, get burned, and learn not to put their hands in the fire.
And some people, believing that they know better than well-known sources, will claim it's a lie, put their hands in the fire, and continue to scream it's a lie even as their hands burn down to charred stumps.