Header Style: check this box to report on the "header style" subscriptions are set to
receive for list postings. Possible header styles are:
Full: normal headers for list postings. List name is always the To: header.
Subject: same as "Full" but a subject-tag identifying the list is added to the
subject header of all postings.
Short: only the bare minimum headers (To:, From: Date:, and Subject:) are included. This setting will break MIME
messages, so should be used only on lists which allow only plain text or for subscribers
using mail clients that cannot handle MIME mail anyway.
Dual: same as "Full" but the main headers are repeated inside the message text as well.
This is to accomodate some old mail software that did not process Internet mail properly, and
is mostly obsolete.
IETF: headers are exactly the same as those sent by the original sender, with
the possible exception of adding a "Sender:" line (depending on the list configuration). This may
break filters on some mail clients that rely on all list mail having certain mail headers look the
same on all list postings.