> Interesting point. Now that you mention it, I can see how the spec
> could be read to mean that MDNs are only generated upon request, given
> the opening sentence in Section 2. Of course, that fits with all the
> keywords currently defined.
> Personally, I've never been stuck on that point. In addition, the
> specification is intended to be extensible and any conversations I've
> had about vacation notices always revolved around MDNs, so I don't think
> that's a requirement one should expect to survive forever.
The intent of the specification is definitely that MDNs be generated only
upon request. There was talk at the time of later doing a specification
for things like vacation messages and change of address notifications,
but nothing came of it.