I have purchased xenforo today and installed it. Everything seems to be fine except email is not working. To test it, i have registered myself as member and i haven't got any email for confirmation. I have tried with every option like default and SMTP. Even when i am trying to manually email somebody, user is not getting that. It is also not throwing any error message, it's just that recipient is not getting emails. To test, you can register at homebuyingforum.com
If you are using the default mail server then you need to check the mail logs with your web host to see what is happening to those emails. When using SMTP you need to confirm the correct mail settings with your SMTP host.
With the default server it is using the mail server that is setup in your PHP configuration (very likely localhost). In that case your web host is the mail server. Mail logs should be available on your server.