Google in lieu of another round of improvement to Gmail’s search function, the company now allow users in Gmail to lets search for email by size also, with offering flexible date options, exact match and other options. Say, for example, to find emails larger than 5MB, you can search for size:5m or larger:5m or to find emails sent over a year ago, older_than:1y.
Here are the details of Google’s Using advanced search help page: Advanced search operators are query words or symbols that perform special actions in Gmail search. These operators allow you to find what you’re looking for quickly and accurately. They can also be used to set up filters so you can organize your inbox automatically. Some of the most useful operators are listed below.