Have you seen this troubleshooting guide for email issues. Open phpmyadmin, and go to ow_base_mail. When you send an email it should populate there; you would have to refresh the page to see it. The platform will hand it off to the mail server once cron runs, and should no longer be visible in the ow_base_mail table. If no emails are going out, you may be having a DNS issue. Some mails don't even use cron. They are sent automatically.

https://wiki.oxwall.com/faq:email-sending-is-not-working