I accidentally sent a file I didn't mean to send, can it be deleted before the automatic deletion

Deleting files manually is only possible for registered and subscribed users. You can delete it by logging in to your personal profile and clicking "Inbox\Outbox". Next, locate the email and click the Delete button.
You can register on the site with the email address with which the files were sent, even after sending them. The list of files previously sent from this email address will appear after registration in the inbox/outbox.