Pirate forms wont sent mails on right address

If you are using the default (non-SMTP) configuration which uses the WP/PHP mail, mails might either land in the spam/junk folders or they might get lost. So, you might not receive the email even if the status against an entry reads the mail has been sent successfully. If you face this, please contact your system administrator. If you continue to face this problem, you can switch to the SMTP configuration to ensure email deliverability.
I got this message in pirate forms how to fix it? Im using new Postman SMTP with it.