You can exclude specific posts from appearing your Automailer emails by excluding those posts in Grow Publisher Portal.
This will also exclude those posts from Grow Search, Recommended Content widgets, and (for Mediavine publishers) the Grow Slidebar Ad Unit.
How To Exclude Posts
Step 1: Navigate to Grow Publisher Portal > Grow Settings > Recommended Content > Pages to Exclude.
Step 2: Click into the Search box and type in a keyword or paste the URL of a post you want to exclude.
Step 3: Once you find the post you are looking for, click the Exclude button in order to exclude the post/page from showing in the widgets.
Step 4: Save your changes!
To include a Post/Page you previously excluded:
Step 1: Simply click the Include button beside the post you want to include.
Step 2: Be sure to save your changes!
You should be able to see these changes right away. If you are still seeing the excluded post in Grow's features, navigating to a new page on your site or clicking refresh in your browser should update it.