I send and receive a lot of big photo files and or graphic files.
They are compressible but not so much.
That’s you. 99% of the e-mail is text, and small amounts of text at that, most compression can shrink pure text by as much as 40%. All the e-mails a person sends in a week can be stored in a couple of KB, that’s a 10 to the third measurement, PB storage is a 10 to the 15 measurement. 5 years ago Teradata launched Teradata 12, 50 PB of compressed data. That’s a purchasable tool. And it’s 5 years old, they’re up to Teradata 14 now.
All of our data is storable within commercially available systems. Let’s not even get into secret stuff the government is often claimed to have access to.