Email It In gives you a personal email address. Send or forward an email to it, and its attachments land in the right folder in your cloud storage: Google Drive (including shared drives), OneDrive, Dropbox, Box or Egnyte.
It works from anywhere that can send email: your own inbox, a phone, a scanner or copier, or suppliers and customers sending files directly. Email It In never needs access to your mailbox. It only sees the mail sent to your Email It In address, and files pass straight through to your storage without being kept.
Routing rules send tagged mail to its own folder: put [invoices] in the subject, or send to you+invoices@emailitin.com. You can also make a folder for each email subject, choose what happens when a file with the same name exists, save the email body, get a delivery notice, or call a web hook for each filed file.
Free plan for light use; Premium removes the monthly and size limits. Running since 2013, with over 11 million files filed.