Barry Warsaw writes:
- is more interesting. What kinds of uses are we talking about? You
see a message in an archive from three years ago and you want to
contact the OP about it? Why not just follow up and contact the
mailing list?
For all the reasons why Reply-To Munging Considered Harmful.
Do you want to be contacted off-list for on-list topics? Well, things
like an email forwarding service could solve that, although I think
it's not worth the effort as much as the first use case. What other
kinds of legitimate third party uses does obfuscation/concealment
prevent?
Obfuscation is a minor annoyance, but concealment is problematic in cases where the email is the identity, eg, matching list posts to issue tracker IDs.
For example, I signed up for and log in to Launchpad as "stephen@xemacs.org", but I have to tell bzr that my ID is "stephen-xemacs". Wow, that's transparent. But at least it's guessable. Getting from "Stephen J. Turnbull <email concealed>" to "stephen-xemacs" is not going to be easy if you don't already know me.