Obligatory video from one of the greatest channels youtube has ever seen: By Default - There is no private email

Recently I added a custom domain to my protonmail account and during the procedure it makes you do this steps (adding SPD, DKIM and DMARC) to pass all the steps. They tell you exactly what records you have to add, where to add them and what the content should be. These guys are great

That’s why you a need a package manager