[Mailman-Users] Parallel list question

[Rob Lingelbach]

I once set this up long ago on mailman but took it down and now need to do it again but forgot how:

Want to have all subscribers to list A receive from, and be able to post to, list B. Purpose is to change the list title shown in the Subject: field, and have different admin options for list B. 

Thank you in advance. 
(And while I'm at it, thank you to those who have worked on the DMARC "enhancements.")

Rob Lingelbach
http://colorist.org