Hi rubenalonsoes,
1) Please check the plugin settings => ‘What to use?’ => change the lines from wp-mail to mail and vice versa.
2) email messages can be marked as spam on the server.
Please choose another email instead of the admin’s one (‘Use this email:’ block) – for example, gmail or similar. Please try to specify your email – for example, gmail or similar in The email address settings in the ‘From’ field instead of User email.If the message is sent, it means that email filtering is set on your server.
3) you should install an extra plugin called WP-mail-SMTP and configure it. Afterwards you should send a test email from this plugin and you will see if the plugin logs have errors. Please view the logs after sending a test letter WP-mail-SMTP and fix the occurring errors. Please pay attention, that it is necessary to set WP-mail-SMTP the same way your contact form is set before sending a message.
Regards,
BestWebSoft Support Team