Despite having highest free storage, sometimes you start running out of space in Gmail. This is due to those large attachment mails which you can never find. They are difficult to find as Gmail does not sorts by size but you can find them by searching by size.
To Search Gmail by Size, Use size: search operator
Search format is
size:[size in bytes]
The search operator searches in bytes by default. You can also use M to search in megabytes.
|Mails with attachment size 5MB or more||size:5M|
|Mails with attachment size 10MB or more||size:10M|
|Mails with attachment size 20MB or more||size:20M|
You can also use multiple search operators together for conveniently finding large mails with special properties. For example: You can also use filename operator to search by file type. For example – filename:(mpg OR mpeg OR avi OR wmv OR mov) searches for mails with videos in attachments. Similarly you can use filename:zip OR rar or MP3 to quickly find space hogging mails.
Google’s free space is shared between all Google products – Gmail, Drive, Photos etc. Transferring attachments from Gmail to Drive will not have have any effect on total storage.