New Yorker email epub to Kindle rejected in recent weeks

[mkgtu]

Amazon used to reject a lot of epubs but lately I've had NO problems for multiple publications.
The only exception is that for the last few weeks The New Yorker epub, emailed to Kindle gets rejected. Four other publications downloaded at the same time went through with no problem.

I suspect nothing can be done. Probably not a recipe issue. But thought I'd report it anyway.

My personal fix:
Since redownloading results in the same problem, I simply convert the downloaded epub to AZW3, delete the original epub, then use Kindle Unpack to "extract KF8 to Epub". The resulting new epub gets emailed to Kindle successfully.

I suppose i could check the original epub for errors using calibre tools, but I'm not sure I'd know how to "fix" any errors. But the above method works for me.