Re: nnimap and crossposting (Re: Moving from nnml to nnimap...)

[Ken Raeburn <raeburn@raeburn.org>]

Simon Josefsson <jas@extundo.com> writes:
>> My experimentation so far (playing with imtest, don't have the guest
>> account and nnimap config set up yet) seems to indicate that the marks
>> won't be propagated.  If this is the case, I think it would be a good
>> idea for the documentation to indicate this.
>
> IMAP doesn't understand the concept of crossposting, I think, so this
> sounds normal.  How does crosspost mark propagation work for nntp
> groups?

Using the xref header, I believe, which as far as I can tell, is
generated on the fly for nnimap, and only lists the current group.

I wonder, is there a way to go through all the groups and ask the
server if a certain set of message-ids are present in each?  It would
probably be painfully slow if there are a lot of groups (I've got over
200 groups in my nnml hierarchy), and would require either staying
connected until all the groups are scanned or storing the data in some
magic place so the scan can be resumed if interrupted.

Worst case, perhaps Gnus could create a variant on the Xref header,
which says which folders the article was going to be copied to, and
leave out the message numbers, but that presumably requires Gnus to
download, edit, and upload each message, and it wouldn't work with
something like Sieve doing the refiling as messages come in, which is
where I'd prefer to get eventually.

>    I suspect it might be possible to implement something like it
> for nnimap by looking in the nnmail message-id split log when applying
> marks to a group (i.e., for each article with new marks, look up the
> message id in the split log and find out what other groups it was
> crossposted to and apply the same mark to it).

That means this split log would have to be permanent, not per-session,
so I could read (and mark expirable across groups) in this session a
message I got during the last session.  That per-server data will get
very big, and slow to scan.

And it would need to be shared between different client systems one
might run Gnus on.  On the one hand, that might not be much worse than
the .newsrc.eld file, but I'd kinda like to be able to browse my mail
on my home server from my Gnus session at work on occasion, and vice
versa, and they really shouldn't have to share all the .newsrc.eld
data.  And isn't it part of the point of IMAP that such data lives on
the server?

Ken