Hi, I have the same problem here. The tenant's SMTP setting are correct and test emails are successfully delivered. I'm evaluating the FusionAuth right now and often delete/re-register users with the same emails. Verification emails are delivered to all users but one. The only thing that distinguish the problem user from the others is the fact I initially registered him via Facebook identity provider, so his email was automatically verified. After that I deleted the user and trying to register with just email (not Facebook). And emails are not delivered. Manually sent SMTP test emails to that address also delivered successfully. I hope this help to investigate.