Re: [tlug] mojibake again (was February Nomikai on Valentine's Day?)

["Stephen J. Turnbull" <turnbull.stephen.fw@example.com>]

Darren Cook writes:
 > On 17/02/2020 06:41, Scott Robbins wrote:
 > > On Mon, Feb 17, 2020 at 12:25:51PM +0900, Andreas Kieckens wrote:
 > >> \#
 > > 
 > > 
 > > This is another that shows up for me (neomutt version 20191207 on CentOS
 > > 7.7.1908) with just a \#
 > 
 > The base64 is broken: there is a blank line and a ")" that should not be
 > there. Your email client is seeing that and thinking it is the message;
 > I guess others are quietly throwing it away.

The former behavior is broken.  The latter is correct, per RFC 2045:

    All line breaks or other characters not found in Table 1 must be
    ignored by decoding software.  In base64 data, characters other
    than those in Table 1, line breaks, and other white space probably
    indicate a transmission error, about which a warning message or
    even a message rejection might be appropriate under some
    circumstances.

Note that MUAs don't "reject messages"; they're supposed to deal with
what they get.

 > Who puts in the X-Rspamd ? Or, if no-one else sees that, then it must be
 > my ISP :-)

That's something in the mail system between Mailman and you.  This is
what I see at the break between the header and the message body:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Message-ID: <fdb4b7c1-9887-aa6a-b385-368a512da28b@example.com>
From: Andreas Kieckens <adgkieckens@example.com>
Reply-To: Tokyo Linux Users Group <tlug@example.com>
To: tlug@example.com
Subject: Re: [tlug] February Nomikai on Valentine's Day?
Date: Mon, 17 Feb 2020 12:25:51 +0900

T24gMi8xLzIwIDE6MDcgUE0sIEVkd2FyZCBNaWRkbGV0b24gd3JvdGU6Cj4gT24gMi8xLzIwIDEy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 > Subject: Re: [tlug] February Nomikai on Valentine's Day?
 > X-Rspamd-Queue-Id: C58ECA5638
 > X-Rspamd-Score: -1.73 / 15.00 / 150.00
 > 
 > )
 > 
 > T24gMi8xLzIwIDE6MDcgUE0sIEVkd2FyZCBNaWRkbGV0b24gd3JvdGU6Cj4gT24gMi8xLzIwIDEy

That's shocking.  Aside from the paren, Rspamd IMHO should not be
adding headers there.  (I bet they do it because otherwise they get
"blank line / lonely paren / blank line" in the middle of the header
which will blow up every MUA. :-þ)

Steve