Here’s my take on this. Recovering emails after the trash has been emptied is a challenging situation, as that action is typically final on the server.
On one hand, your most promising path for recovery lies with local backups. Since you use a MacBook, your best bet is to check your Time Machine backups. If you use the Apple Mail app and Time Machine was active, you can restore your Mail data to a point in time before you cleared the trash.
On the other hand, direct server-side recovery is a long shot. While you could contact Apple Support, their ability to recover permanently deleted data is not a standard service and success is rare. Most third-party recovery tools focus on files stored locally on a device, so they are unlikely to help with data purged from iCloud’s servers. I would investigate the Time Machine option first.