plugins – Is there a wordpress operate prohibit public e-mail id for registration like as is_email()

I’m attempting to implement person registration solely from the work e-mail not with public emails like Gmail, yahoo, outlook, and so forth
person registration might be by way of solely with a enterprise e-mail I’m able to implement a sound e-mail however not work e-mail restriction.

    if (!is_email($signup_email)) {
        echo json_encode(array('signedup' => false, 'message' => __('Invalid E-mail!', 'piperegistration')));
        exit();
    }
    if (email_exists($signup_email)) {
        echo json_encode(array('signedup' => false, 'message' => __('E-mail already exists!', 'piperegistration')));
        exit();
    }
    if (6 > strlen($signup_pass)) {
        echo json_encode(array('signedup' => false, 'message' => __('Password too brief. Please enter at the least 6 characters!', 'piperegistration')));
        exit();
    }

I’m nonetheless within the studying part so please assist me out