Find big size files in Gmail
This is a way to list all your big sized emails in Gmail
Since there is no way to sort your Gmail-emails by size, you will have to do something else
Search for emails by size and more in Gmail
If you are looking for ways to find your big size messages/emails using search in Gmail.
If you want to find emails larger than 2MB, type this in the search-field:
“larger:2m” – which will show you all the emails larger than 2 MB in your inbox