I have now tried mu4e and I don't like it nearly as much as notmuch, so
I'm sticking with this and aim to help out where notmuch falls short on
tag syncing between machines :-)

David Mazieres <dm-list-email-notmuch@scs.stanford.edu> writes:
> the complexity of altering files is not worth it.

I agree. Immutability is a great thing. I like the proposed approach of
having a single "archive" Maildir folder (which notmuch really uses),
and then copying files into other folders to flag them as having a tag
or not (but these folders are not indexed by notmuch, avoiding
duplication problems).

It sounds like Gmail would play well with this setup and I assume most
IMAP servers will be smart enough to treat these as references to the
same immutable message. There is a potential persistent memory cost on
the client side due to the excessive copying, but somebody pointed out
that hard links would solve the problem locally. That just means the
IMAP sync applications just need to be a little smarter about how they
communicate with the server. I'm not averse to writing a tailored IMAP
syncing app, although it would be in a real language like Scala or
Haskell :-P Some sick part of me is also bizarrely intrigued by writing
it in elisp.

I am going on an extended holiday very shortly, but I hope one of you
does some more feasibility testing on this during that time: when I
return I will most likely help out with contributions.


> what you want is an imap server built on top of the notmuch library

That wouldn't appeal to me: I want to continue using my gmail account as
it is well integrated with a variety of other services, gratis and the
spam filtering is incredibly strong.


-- 
Best regards,
Sam