juggling for recipients in headers
Strip nodup recipients from both the
Cc headers, and juggle recipient headers so that the list address is always in the
To field. This might address the other major complaint against no-reply-to-munging, recipient proliferation.
From http://wiki.mailman.psf.io/DEV/Mailman%203.0?action=diff&rev2=30&rev1=28 -- a TODO for the Mailman 3.x series.