Re: Read/process mbox file in Gnus

[Skip Montanaro <skip.montanaro@gmail.com>]

I was out riding around (new bike day <https://flic.kr/p/2k3WWdr> 😀) and
it occurred to me that the way I am using mbox files is just as a
transmission tool. All mail readers save some detail about the current
state of affairs (read, deleted, message order, etc). I think most probably
keep this information out-of-band somewhere, in something akin to a
database. VM keeps that information in the mbox file in the form of a bunch
of X-VM-whatever headers. This works perfectly for how I consume these
messages. My workflow on mail.python.org generates a file named u.mbox. I
download it and load it into VM, saving messages of interest to either
s.mbox or h.mbox. Those two files are uploaded back to mail.python.org,
then all three local files [ush].mbox are deleted. The next time I process
new unsure messages, I start from scratch. Deleting an mbox file
effectively zaps all metadata for that file's messages and I start anew
next time.

I'm going to guess Gnus saves metadata in ~/.newsrc.eld. It's not clear how
well it would take to me pulling the rug out from under it by replacing the
previous u.mbox file with a completely new one without also somehow
performing careful surgery on its metadata (assuming I also use it as my
normal mail reader).

Skip