Re: [PATCH] private message id

[Russ Allbery <rra@stanford.edu>]

Łukasz Stelmach <lukasz.stelmach@iem.pw.edu.pl> writes:

> I'd like to share an idea, and a patch that implemnts it, to make
> Message-ID slightly worse source of data tracking down an individual who
> uses multiple accounts on one machine. All message get the same fqdn
> part so it is quite obvious they are sent from the same machine.  I
> know, there are Received headers but they are not as easy to parse, and
> may be a lot less accurate behind a NAT.

> I propose a Message-ID consiting of unique-id%e-mail-address grabbed
> from the From header. Take a look at the ID of this message.

In theory, this is a minor violation of best practices for generating
Message-IDs because you're "stealing" message IDs from the space owned by
the e-mail address domain and may conflict with some message ID generation
algorithm used separately by the owner of that domain, thus resulting in
message ID collisions.  In practice, though, the addition of the username
makes that very unlikely, so I doubt it would be a practical problem.

Seems like a fairly good idea to me.

-- 
Russ Allbery (rra@stanford.edu)             <http://www.eyrie.org/~eagle/>