If something isn't working the way you expect, this section is the place to start. Most issues fall into a small number of categories — emails not arriving, verification problems, DNS not verifying, or login trouble.
Each article walks through the most likely causes in order, starting with the simplest things to check. Work through them top to bottom and you'll usually find the fix quickly.
If you've gone through the relevant article and still can't figure it out, open a support ticket and include what you've already tried — it speeds things up considerably.