Duplicate email on edit post

Hi, I have a front-end form and was not receiving emails on new posts, so I applied the PHP code suggested in Functions.php and that worked perfectly. I now receive an email for new posts (custom post type). However, we also send notifications when the post is edited, and now it is sending a “post updated” email as well as a “new post” email when the post is edited. Is there any way to stop the “New post” email when the post is edited? Thanks so much.