Turn off Yahoo mail icons

No, there's no way to retrieve them short of asking all people who sent you the email during the period it was deactivated, to send the emails again

What I would do, is marking things that I know they're spam, and creating a filter for them to auto-delete them. It will decrease dramatically the number of emails even get to your spam folder.

• You can follow the same steps as here but select the trash instead of creating another folder.