Subject: bug#79307: 30.1; Rmail: MIME decoding failed

From: Jeremy Bryant <[email-masked]>
Date: Tue, 26 Aug 2025 20:51:51 +0100

Francesco Potortì <[email-masked]> writes:

> Rmail says: "MIME decoding failed: (error Message is not a valid RFC 822 (or later) message)" when reading the attached mbox.  Apart from the error message, everything looks ok at first alright.  Sorry, no time to look at it at this the moment.
>
> To reproduce:
> - save the attachment
> - emacs -Q
> - C-u M-x rmail RET
> - the name of the saved attachment RET
>
> For me, Rmail apparently does the right thing, but prints the above error message.
>
>
>
> In GNU Emacs 30.1 (build 2, x86_64-pc-linux-gnu, X toolkit, cairo version 1.18.4, Xaw3d scroll

FWIW
On Emacs 30.2 with the above recipe it also gives the same error message.