Wondering which email messages are eating up all the Gigabytes of space that you have in your Gmail mailbox? There are Google Scripts and external web apps that let you discover all the space-hogging email attachments but you don’t really need them anymore.
Gmail supports an undocumented “size” search operator that will let you quickly find all the big emails in the mailbox whose size exceeds a particular threshold. The search syntax is:
size:[size in bytes]
You may specify the size in MB as well which makes it a lot easier. For instance, size:5MB (or say size:5M) will find all Gmail message that are 5 MB or greater in size.
In addition to size, you can use search operators like “larger”, “larger_than”, “smaller” and “smaller_than” to find files of any particular size. A combination of these size search operators is possible too. For instance, the following Gmail search query will find all emails with attachment sizes between 5 MB and 8 MB.
Once you have spotted the large emails attachments that are taking too much space, apply the #googleDrive label to directly save those attachments to Google Drive before deleting them from your Gmail mailbox.