Is there a condition where approval emails do not get sent to invoice (and expense) approvers?

Summary:

Approvers do not always receive approval emails

Content (required):

I know that you can set the size of attachments and number of attachments so that if you exceed, the attachments are sent as links. But are there conditions where the emails are not sent at all?

Version (include the version you are using, if applicable):

23A

Code Snippet (add any code snippets that support your topic, if applicable):