MBOX-Line: From echappa at gmx.com  Fri Mar 13 12:28:39 2015
To: imap-protocol@u.washington.edu
From: Eduardo Chappa <echappa@gmx.com>
Date: Fri Jun  8 12:34:54 2018
Subject: [Imap-protocol] DKIM signatures on this list
In-Reply-To: <20150313164848.24608.qmail@ary.lan>
References: <20150313164848.24608.qmail@ary.lan>
Message-ID: <alpine.LSU.2.20.1503131305190.2099@linux-0rhy>

On Fri, 13 Mar 2015, John Levine wrote:

> Many people imagine that an invalid DKIM signature says something bad 
> about a message.  They are mistaken, no matter how often they repeat 
> that misconception.  There is nothing in DKIM that says anyone should 
> remove signatures from incoming mail for any reason.  If a signature 
> doesn't validate, the correct thing to do is to ignore it.

The point of a signature is to have a way of verification of the message 
as sent and received. If "you" received a message from your boss saying "I 
approve that you spend ten thousand dollars in the company party" and the 
signature of such message would not validate, that would certainly not be 
a situation where "you" would say "the correct thing to do is to ignore 
it." Let me put it this way. There is a purpose in the signature, and if 
it does not validate, that is serious matter. When it is broken by 
software (even if the intentions of that software are good) that is not 
good either. I know IMAP servers can break S/MIME signatures in messages 
with attachments by adding a trailing CRLF to messages, or some mailing 
list processors can fold lines and break S/MIME signed messages. Alpine 
(my MUA) goes to greater lengths to validate signatures than any other MUA 
that I know of.

The original message is correct. The mailing list manager modifies 
messages sent to this list. As a general point, that is not good; in 
some/many particular situations, it is probably irrelevant, but certainly 
not to be always brushed off as "the correct thing to do is to ignore it."
There is a point as to why that standard was invented. That should be 
considered too, even if it is not important for your particular case.

-- 
Eduardo

