In a recent communication, Amazon has alerted Kindle users about significant changes set to take effect from next month. The notification pertains to the phasing out of support for sending MOBI (.mobi, .azw, .prc) files through the “Send to Kindle” feature, starting November 1, 2023. This change, as News18 pointed out, specifically impacts users attempting to send MOBI files via email and Kindle apps on iOS, Android, Windows, and Mac.
Wait, does Kindle handle epub now?
No, but you can send one through the email service and it will be automatically converted.
I only ever send in epub format. In the article it clarifies that Amazon recommends the sending of epub.