There are three scenarios causing issues with the mail form:
1. The Recatpcha has not been implemented or the keys are incorrect. Please double check the Recapthca keys
2. Your test emails are going to your spam folder. If you use the same address of the recipient or use subject ‘Test’ sometimes these emails are sent to spam.
3. Your domain cannot send emails. Check with your hosting provider if you can send emails from your domain.