I sent out three new sieve drafts last week that may be of interest:
fileinto :copy, redirect :copy -- keyword parameter that
prevents cancelling the implicit "keep".
Deleting, adding, and changing message header fields.
Sequential execution of (unrelated) sieve scripts by the
environment. A meta-feature -- it doesn't define new sieve
language elements -- that's interesting in particular in
contrast to Cyrus's "include" draft.
There may or may not be another one for fileinto in the wings.
It's about Kjetil's open issue 0.3 b):
Some implementations of "fileinto" create IMAP folders on the
fly if they don't exist; others don't. (They redirect to
the inbox instead.) Sieve doesn't proscribe either way.
My own implementation used to only reuse existing folders; but now
that we're thinking about creating them on demand in conjunction
with the "variables" extension, I'm getting requests for a way
for a user to express their intention; something like
fileinto :create "If it doesn't exist, create it"
fileinto :exists "If it doesn't exist, redirect to INBOX."
or something in that area.
Is anyone hearing similar requests from their users?
Have you thought about the issue and come to conclusions for
your own releases?