Get post_author email for Zapier Integration

There’s no direct way of getting the post author’s email from a post. You can get the email by using the author ID, which is present in standard WP_Post object.

$post_author_id = intval( $post->post_author );
$post_author_email = get_the_author_meta('email', $post_author_id);

Or if you just have the post ID

$post_author_id = intval( get_post_field( 'post_author', $post_id ) );
$post_author_email = get_the_author_meta('email', $post_author_id);

Or if you want, you could also hook custom function to save_post action and save the author email to the post’s meta, when the post is created. Then you could get the email with get_post_meta() using post ID and the custom key you used to save the meta.