Does L-Soft have plans to add support for the use of the List-Id header
described in RFC 2919 <http://www.ietf.org/rfc/rfc2919.txt>? If so, when?
If not, why not?

It provides a reliable method of identifying list messages. The 'To:' line
is not reliable filter fodder. It usually contains the list address, but
some subscriber option settings cause the recipient's address, rather than
the list address, to appear on the 'To:' line.

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Paul Russell
Senior Systems Administrator
OIT Messaging Services Team
University of Notre Dame