Spam Filter Frustration

So like any normal Web developer, I setup my own domain and website and also setup email services. I start mailing people and then realize my email is caught by spam filters!
How annoying! And now I have to argue with my ISPs on why the IP addresses of their mail servers are on watchlists of spam filters. In the meantime, my email is being held for 4 hours or more OR not even being delivered at all.
WTF. This isn’t supposed to be how spam filters work.