bug#31590: 25.1; malformed email address in RMAIL

[Eli Zaretskii <eliz@gnu.org>]

> From: Olivier <Olivier.Nicole@cs.ait.ac.th>
> Date: Fri, 25 May 2018 10:54:14 +0700
> 
> When trying to read the new messages in RMAIL, I get the error
> "Malformed email address" on one message (it did happen in the past,
> once every 2 years maybe). As a consequence, messages following the
> malformed one cannot be read and no message is deleted from the INBOX,
> resulting in reading the same messages over and over again.
> 
> This time I managed to identify and keep a copy of the
> concerned message.
> 
> I am reading my mail through POP3, with movemail installed as part of
> mailutils-3.1.1_3.
> 
> Emacs installation is pretty standard, build from FreeBSD ports.
> 
> Trying to read the same message with Thunderbird (POP3 and IMAP) did not
> give any error message.
> 
> I have been using Emacs for over 30 years and I have always been
> completely happy with it, but that bug bugs me.
> 
> Attached is a copy of the message.

Thank you for your report.

Trying to read the message you attached gave me a different error:

  Invalid mbox file

If I use the 'C-u g' command in Rmail to get new mail messages from
that file, I get this error message:

  Message is not a valid RFC2822 message

The message you attached is indeed invalid for the mbox format: it
doesn't start with a "From <address>" line, which is mandatory for the
mbox format used by Rmail.  Once I fixed that (by adding the missing
"From" line manually), Rmail could read and display that message just
fine.

When some email message in the received mbox file is invalid, Emacs
cannot continue processing email, because doing so could completely
ruin your inbox.  Emacs expects you to manually repair the incoming
mbox file, and then try again.  So I think Emacs does TRT in this
case.

So the problem with malformed email address cannot be reproduced with
this message.  I tried both Emacs 25.1 and the current release
candidate of Emacs 26.1, and they both show the error messages
described above, not the one you reported.  From your bug report, I
see that the "Malformed email address" message comes from the movemail
program, not from Emacs.  I don't find such a message in the version
of movemail we distribute with Emacs, and since you say you have
Mailutils installed, I guess you should report this problem to the
Mailutils developers.