[Mailman] Update Mailman to 2.1.19

[Dirk Stöcker]

On Thu, 28 Apr 2016, Tom Hughes wrote:

> On 28/04/16 10:05, Dirk Stöcker wrote:
>
>>  I'm currently in the process of implementing DKIM and DMARC and noticed,
>>  that OSM mailinglists, especially josm-dev in my case, break correct
>>  signatures.
>
> You mean they correctly implement decades old email protocols and don't 
> attempt to force the world to abandon mail forwarding by coercion?
>
> DKIM and DMARC by design do not allow email forwarding. Unfortunately for 
> their designers there is an entire world out there that relies on exactly 
> that, and that doesn't change just because you announce that it should. They 
> are basically broken by design.

I think that's wrong. DKIM and DMARC do not prevent forwarding. What you 
mean is SPF. But DMARC is "SPF or DKIM" not "SPF and DKIM". Thus 
forwarding is perfectly ok as long as the signed components of the 
original mail are not modified.

E.g. JOSM mailinglist could conform to DKIM when neither subject not body 
of the mail would be modified. Only appending additional headers (e.g. the 
email list headers).

As DMARC has a reporting feature I see that many fordwarders leave the 
DKIM signature intact. And I also see a part of the large amount of spam 
sent with my domain name and that exceeds the legitimate mail by a factor 
of 100.000).

SPF is not really that helpful I agree, but DKIM can help when forwarders 
do not modify the core message elements which they shouldn't do anyway.

> Even then I personally would be against changing the setting in question 
> though no doubt I will have to do so :-(

postfix mailinglist works with DKIM and the only difference is the missing 
change to the subject field and no additional malinglist text in the 
message body. I think that is acceptable, especially when using a proper 
mail programm which shows you the additional mailinglist headers for 
subscribe, unsubscribe, ...).

Ciao
-- 
http://www.dstoecker.eu/ (PGP key available)