I signed up for the Business Trial account that is supposed to provide 9Tbs of space. I downloaded and installed the Desktop app and attempted to back up some folders containing photos from my 4Tb drive.
However, I would get "not enough space" errors. Dropbox email support said I only had the free 2Gb account, and when I sent the email verification for the trial account, they ignored me and just closed the ticket. Both use the SAME email address and when I log in online, it says I have the Business Trial account.
I then contacted Dropbox chat support, but they said that Dropbox creates copies of my files locally before they can be copied to the cloud and that's why I get out of space errors. This doesn't make sense, as that would mean my drive would need to be less than 50% full before I could upload my stuff.