[Mailman-Users] Mailman not showing sender's name for DMARC domain policy=reject

[Gordon Dickens]

Hello,

I am runningseveral mailing lists with mailman version 2.1.18-1. Oneof 
my mailing lists does not ever show the sender's name in the From: 
headerfor DMARC domain policy=reject while the rest of my lists do show 
the sender's name in the From: header. I have compared the individual 
list settings and cannot find anything different.  The list settings for 
the list that isn't showing the sender's name are as follows_:

_General Options:

     from_is_list = No
     anonymous_list = No
     first_strip_reply_to = No
     reply_goes_to_list = "This list"

Privacy options > Sender filters:

     dmarc_moderation_action = Munge From
     dmarc_quarantine_moderation_action = Yes

My understanding is that one of the following should be displayed for a 
DMARC domainpolicy=reject:

The author's display name fromtheir From: header
      or;
If none and from a list member, the members real name from the 
membership list
      or;
If none, at least the local part of the emailaddress.

Does anybody have any idea what setting that I need to change to fix this?

Thanks,

Gordon