Open Gmail
In the search bar, type older_than:1y
Press Enter
Select the emails you want to delete
Click the Delete icon
To delete all matching emails, click the Select all conversations checkbox if shown
Click the Delete icon
Open the Trash folder
Click Empty Trash now
To delete by date, search before:2024/01/01
To delete by sender, search from:sender@example.com older_than:1y
To delete large old emails, search larger:10M older_than:1y