Wow. In combination with
this, this is going to be magic! What we've always dreamed of!
The link goes to a tutorial to have your [my.kobo]@gmail automatically send all email attachments to your Google Drive. So, set up your Kobo with spMatti's lovely thingeme, and setup your new google account with Amit Agarwal's script (easy), and you can send emails to your Kobo, just like the handy Kindle option we're all jealous of!
Edit: there's another explanation of how to make gmail put attachments into Google Driver
here. The link to the spreadsheet you need doesn't work in this explanation, but it does show you in more detail how to add a label to the relevant emails.