Re: mail splitting to another backend

[Ted Zlatanov <tzz@lifelogs.com>]

On Fri, 18 Apr 2003, jas@extundo.com wrote:
> I take back my idea -- nnimap cannot split mail from mail-sources,
> only from a IMAP mailbox.  This is probably not very difficult to
> fix, though.  Just replace the part that fetches mail from the
> INBOX, before it is splitted, with some code that gets mail from a
> mail-source.  But to not interfer with normal mail-sources, I think
> this would mean adding a nnimap-mail-sources.

While your idea has its uses, I'm not sure it helps here.  What I want
is very simple, and can't be achieved for the general case with the
one-time cross-splitting you demonstrate.  I just want users to say
"split to destination nnxyz+abc:mail" in nn{mail|imap}-split-fancy and
have it work, like users would reasonably expect since the rest of
Gnus works with this convention.

What's below is generic enough that any backend can use it when
splitting, not just nnmail/nnimap - I only looked at nnmail.el though
so please correct any inaccuracies.

1) if nnmail-article-group returns a normal (non-prefixed) group name
   do normal splitting (incidentally, should the ":" character be
   allowed in group names?)

2) if nnmail-article-group returns a prefixed group name outside the
   current server, put the message in a "split-queue" group and
   remember the article number and the destination, perhaps with an
   extra header inside the article body to make the destination
   persistent even if the queue redistribution fails.  Once mail
   splitting is done, the queue group is redistributed by moving the
   articles to their destination; this is fairly easy and any failed
   moves will simply remain in the queue group until the user creates
   the destination or deletes the articles.

3) if nnmail-article-group returns a prefixed group name that refers to
   our own server (I have not yet figured out how to detect this),
   either strip off the prefix and proceed as in (1) or just do (2),
   it shouldn't make a difference.

I'd be happy to help implement the above, but I doubt I can do the
whole thing on my own.

Thanks
Ted