Combine this search with the older_than parameter to find mail older than a certain period. For example older_than:2y will find mail more than 2 years old; older_than:30d finds mail over 30 days old.
There are also some 3rd party products in the Google Apps Marketplace that will help you find large attachments, such as Free Space from Backupify and Find Big Mail.
Let us know what you think of this tip in the comments below.
