我正在尝试从自定义字段动态获取收件人电子邮件，并使用字符串替换来修改联系人表单7收件人电子邮件 . 联系表单正在发送，但似乎没有更改收件人电子邮件，因为我没有收到电子邮件 .

<?php
function wpcf7_dynamic_email_field( $args ) {

    $dynamic_email = '';
    $submission = WPCF7_Submission::get_instance();
    $unit_tag = $submission->get_meta( 'wpcf7-f3936-p3933-o1' );

    // get the post ID from the unit tag
    if ( $unit_tag && preg_match( '/^wpcf7-f(\d+)-p(\d+)-o(\d+)$/', $unit_tag, $matches ) ) {
        $post_id = absint( $matches[2] );
        $dynamic_email = get_post_meta( $post_id, 'email', true );
    }
    if ( $dynamic_email ) {
        $args['recipient'] = str_replace('emailtoreplace@email.com', $dynamic_email, $args['recipient']);
    }

    return $args;
}

add_filter( 'wpcf7_mail_components', 'wpcf7_dynamic_email_field' );
?>

我正在运行CF7 4.5.1和PHP 5.3 am我在这里遗漏了什么？

php email contact-form-7