Our plugin is using wordpress mail processing, so it just sends a request to wordpress to send email on behalf of the plugin and wordpress should send email using the mail server that you have setup on your hosting. You can read more info in this article: https://www.wpbeginner.com/wp-tutorials/how-to-use-a-free-smtp-server-to-send-wordpress-emails/
You can also test your emails by using this plugin: https://wordpress.org/plugins/check-email/
