Mysql + extimal

Mysql + extimal-general Linux technology-Linux technology and application information. For more information, see. Hello everyone, I am a newbie. I recently studied the mail section, mysql + extmail. My mail can be normally sent using postfix + mysql, in addition, my extmail front-end can all be accessed normally, but I cannot use extmail to send emails normally (the interface is always sending), and use postix to send emails securely, it can be accepted normally on the extmail interface. I 'd like to explain the reasons.