Nathaniel Borenstein writes:
deleted messages are a real problem for post hoc thread computation
and force UAs to rely on subject-based matching
False. The trn program does a fine job of merging the References fields
from many messages into a coherent thread picture, even when messages
have been deleted.
Maybe putting more information into each message would make trn's job
easier---but maybe not. Some sort of merging is obviously necessary as
soon as there are two independent replies to a single message; I see no
evidence that this software would be simplified by any of the proposals
here.
---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago