silverstripe-blog/docs/en/configuring-notifications.md

Configuring notifications

Configuring whether notifications will send to authors of blogs if comments are spam

Default behaviour using the silverstripe/comment-notifications module is to send notifications of comments to authors regardless of whether they are spam or not.

In some cases you may wish to not send a notification email to an author if the comment is spam, this is a configurable option.

Add the following into your yaml config:

SilverStripe\Blog\Model\BlogPostNotifications:
  notification_on_spam: false