A few years ago I had to clean up my work account because I hit a 50 Gb capacity. Today I have 20 Gb used again. And I'm a single low level (in the hierarchy) engineer. Emails from different automated systems and confluence produce gigantic amount of not-quite-spam (because it is sometimes very useful).

If they had 500 Tb of emails, maybe it was a concern, but 45 Gb looks like a single account breach. Maybe some interesting confidential emails sent company wide, or department wide, but probably hardly anything worth it. That's why I think Boeing didn't pay and was right to do so.