Can't Email Calibre eBook Files to Kindle

Abrasrose · 03-24-2025, 04:29 PM

I am using Calibre 8.0.1 and I'm trying to email ebooks from the calibre library on my MacBook Air to kindle, not directly from Calibre itself.

First, I converted the files to ePUB in Calibre. Then, I verified that my kindle email address was correct and that my personal email address is on my accepted senders on Amazon.

Amazon did not accept the files due to unsupported format. The error message is: E001 - Unsupported File Format:

* smime.p7s

I spoke to a Amazon customer service rep and he said that the error message referred to a digital signature on the original file.

I had this problem with both open source books and books I stripped the DRM off many years ago.

Does anyone know how I can format the books so Amazon accepts them?

DNSB · 03-24-2025, 05:56 PM

That file format says that your email was digitally signed. The signature shows as a file attached to your email so what Amazon received likely included the epub and the p7s files as attachments. I would have expected that Amazon's servers should be bright enough to disregard the p7s file as a file attachment but live and be disappointed. You could try disabling signing email going to to your Kindle depending on how your email client configures that setting.

Have you tried using calibre to send the ebook using an email server? I've been using GMX for the purpose, you just need to remember to enable POP3 & IMAP under Settings => POP3 & IMAP from the GMX webpage.

Abrasrose · 03-25-2025, 11:19 AM

Thank you! I'll give it a try. I'm not sure how to use GMX, but that's what google is for!

03-24-2025, 04:29 PM	#1
Abrasrose Enthusiast Posts: 25 Karma: 10 Join Date: Aug 2015 Device: kindle	Can't Email Calibre eBook Files to Kindle I am using Calibre 8.0.1 and I'm trying to email ebooks from the calibre library on my MacBook Air to kindle, not directly from Calibre itself. First, I converted the files to ePUB in Calibre. Then, I verified that my kindle email address was correct and that my personal email address is on my accepted senders on Amazon. Amazon did not accept the files due to unsupported format. The error message is: E001 - Unsupported File Format: * smime.p7s I spoke to a Amazon customer service rep and he said that the error message referred to a digital signature on the original file. I had this problem with both open source books and books I stripped the DRM off many years ago. Does anyone know how I can format the books so Amazon accepts them?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Kindle Voyage not receiving files even though Calibre sent out email successfully	elegiacally	Devices	1	10-21-2019 11:45 PM
Can't send ebook by email to kindle	Elpinche	Devices	1	10-20-2016 12:52 PM
Email converted ebook to Kindle failure	Colc	Library Management	8	09-21-2015 06:42 PM
Associating ebook files with Calibre ebook viewer	zobop	Library Management	1	06-24-2012 11:07 AM

03-24-2025, 05:56 PM	#2
DNSB Bibliophagist Posts: 46,073 Karma: 168961900 Join Date: Jul 2010 Location: Vancouver Device: Kobo Sage, Libra Colour, Lenovo M8 FHD, Paperwhite 4, Tolino epos	That file format says that your email was digitally signed. The signature shows as a file attached to your email so what Amazon received likely included the epub and the p7s files as attachments. I would have expected that Amazon's servers should be bright enough to disregard the p7s file as a file attachment but live and be disappointed. You could try disabling signing email going to to your Kindle depending on how your email client configures that setting. Have you tried using calibre to send the ebook using an email server? I've been using GMX for the purpose, you just need to remember to enable POP3 & IMAP under Settings => POP3 & IMAP from the GMX webpage.

03-25-2025, 11:19 AM	#3
Abrasrose Enthusiast Posts: 25 Karma: 10 Join Date: Aug 2015 Device: kindle	Thank you! I'll give it a try. I'm not sure how to use GMX, but that's what google is for!

Advert