Dovecot mailing list and DKIM

[Kevin N.]

Hello everybody,

Going through my mail logs I noticed that a couple of messages from the 
Dovecot mailing list failed DKIM validation.

For example, this one has failed: 
https://markmail.org/message/te7tycmpiutw4kia

'opendkim-testkey' shows that the key is OK.

The messages in the example comes from yahoo.com, however other messages 
from yahoo.com, ones that are not sent through the mailing list, are 
properly validated.
The failure is not specific to yahoo.com since a couple of other 
messages from other domains, sent though the mailing list, also failed 
DKIM validation.

However, the vast majority of the messages from the list properly pass 
DKIM validation.

 From what I have read, mailing lists in general do not play very well 
with DKIM or SPF and the Dovecot mailing list also had some issues with 
this in the past.

With the Dovecot mailing list, I am a bit curious about why the vast 
majority of the messages from the list pass DKIM validation while a 
couple of them fail.

Does the Dovecot mailing list software alter the message in a way that 
causes the failure? Or is there something else going on?

Any thoughts?


Cheers.