I was just browsing Threads and fell into the wormhole of reading old posts by mtamblyn (Kobo CEO) and he mentioned a means of emailing content to your Kobo (if it natively supports DropBox).
I haven't yet tried it yet but see
https://www.kobo.com/blog/how-to-ema...s-to-your-kobo
Ah.. looks like unfortunately that feature requires a PAID dropbox account.
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