OT DMARC question

[Paul R. Ganci]

I notice that postfix generates bounce messages that without going 
through some effort do not get DKIM signed. I have setup my incoming 
gateway server so that messages to my email subscribers are bounced 
using a local_recipient_map. However I received a report from 
linkedin.com because a Linked-In subscriber sent a message to an email 
address of a non-existent local user. Linked-In flagged the 
Mailer-Daemon bounce message. It seems to me even if the message was 
DKIM signed the fact that the Return-Path header is <> would still cause 
a mismatch that should not pass the DMARC requirements. I was wondering 
how others handle this problem or is it really just a misconfigured 
Linked-In server? It is ironic that a bounce message resulting from a 
message to a non-existent address sent from linkedin.com would generate 
a DMARC fail by linkedin.com.
--
Paul (ga...@nurdog.com)
cell: (303)257-5208