D. J. Bernstein wrote:
Bruce Lilly writes:
Some people use multiple UAs, possibly at multiple locations. Anything
that requires extensive configuration is a problem.
Even without Mail-Followup-To, having to manually configure several MUAs
is a pain for the user. These users need configuration-sharing tools.
There are a couple of cases worth mentioning:
1. multiple copies on different hosts of the same type of MUA. These
can usually be handled by copying some sort of configuration file.
2. different UAs, whether on one host or different hosts. Because
different UAs have different feature sets, they necessarily
require separate configuration.
Any good configuration-sharing tool will also handle Mail-Followup-To.
Why on Earth would you expect a configuration tool to handle an
undefined field?
Also, some people read lists via a web archive; an MUA has no way to
determine that.
If the user wants to set Mail-Followup-To for a list, he tells the MUA
about that list. End of problem.
If he is using some obscure UA that actually notices that non-standard
field. *And* if everybody else also does.
Yes, there are many situations where the MUA can reasonably do this by
default, saving even more time, but we're talking about a trivial amount
of user effort either way. This is once per list, not once per message!
Once per UA, per user, per list. That's still a lot of configuration
for a user who uses multiple UAs and subscribes to multiple lists.
There's no guarantee that any implementation will be able to
appropriately handle messages sent to multiple lists, and issues
other than mailing lists aren't addressed at all.
And people change mailing list subscriptions (e.g. when they go on
vacation).
Someone who doesn't really monitor the list probably isn't setting
Mail-Followup-To in the first place. Anyway, what's your point?
Reconfiguration every time a list subscription changes. A PITA.