I often encourage readers do download MOBI files from Smashwords and email them (via Amazon's Kindle email) to their Kindle to read. I can thus easily give away free books even if they aren't on Kindle Unlimited.
That will be a no-no by the end of 2022.
New Kindle ereaders will only support epub, which has become the gold standard for ebook formats. I'll have to tell readers to send themselves epub files, which they can download from Smashwords.
MOBI, which has been unique to Kindle, has been the platform's software since I started publishing in late 2009 and early 2010. It feels a bit like losing a notebook that has all the information you need for a test.
For authors uploading books in MS Word (as I do), there will be no difference. And I can still mail myself long grocery lists as PDF files (they arrive as documents, not books).
This is the email I received from Amazon. It's geared to customers who email things to their Kindle, not authors.
Dear Kindle Customer,
Thank you for using the Send to Kindle service to send personal documents to your Kindle library. We wanted to let you know that starting August 2022, you’ll no longer be able to send MOBI (.mobi, .azw) files to your library. Any MOBI files already in your Kindle library will not be affected by this change.
MOBI is an older file format and won’t support the newest Kindle features for documents. Any existing MOBI files you want to read with our most up-to-date features for documents will need to be re-sent in a compatible file format.
Also, compatible formats now include EPUB (.epub), which you can send to your library using your Send to Kindle email address. We’ll also be adding EPUB support to the free Kindle app for iOS and Android devices and the Send to Kindle desktop app for PC and Mac.
If you have any questions, please visit our help page or contact our Customer Service team.
The Kindle Team
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