muchsync - synchronize notmuch mail across machines
Notmuch is a nice mail indexer with front ends for emacs and vim. If you like the idea of fully-indexed, tag-based email like gmail, but you don’t want a cloud- or web-based solution, then notmuch may be for you. However, notmuch stores all of your mail locally on one machine. Hence, until now, if you wanted the full benefit of notmuch tags, you could only conveniently read your email on a single machine.
Muchsync brings notmuch to all of your computers by synchronizing your mail messages and notmuch tags across machines. The protocol is heavily pipelined to work efficiently over high-latency networks such as mobile broadband. Muchsync supports arbitrary pairwise synchronization among replicas. A version-vector-based algorithm allows it to exchange only the minimum information necessary to bring replicas up to date regardless of which pairs have previously synchronized. Muchsync requires storage proportional to the number of replicas plus the number of email messages you have. It consumes bandwidth proportional to the number of replicas plus the number of new/changed messages. In practice, the per-replica data is tiny (just two 64-bit numbers per replica, independent of how many messages you have), so there is no penalty for having many replicas.
To set up muchsync, you must install it on both your mail server and
each machine that will replicate your mail. To create a new replica, you
need to give muchsync two pieces of information: 1) the name of a remote
machine currently storing your email, to which you must have ssh access,
and 2) the name of a local directory muchsync can create to store a copy
of your mail. If the remote machine is
SERVER and the
destination directory is
$HOME/inbox, you would run:
muchsync --init $HOME/inbox SERVER
Initialization will create a
for you based on the one on
SERVER. Note that if you’ve run
SERVER can be any replica; it doesn’t have
to be your main mail server. This command will download and index all of
your mail. Initialization can take a very long time because it
builds a full text index on a single CPU. This is a limitation of how
notmuch tracks threads, which makes it impossible to parallelize
first-time index creation.
Once set up, using muchsync is as easy as typing this each time you want to check for new mail:
That command brings the client and
SERVER up to date
with any tag and message changes, and should generally run efficiently
if you don’t have much mail to download. If, after using the above
command to synchronize your desktop with a server, you also want your
mail on a laptop, you can push the mail from your desktop to the laptop
To build muchsync, you will need a C++11 compiler and the headers and libraries from notmuch, Xapian, SQLite3, and OpenSSL’s libcrypto. To run muchsync, you will need ssh.
Or, to contribute, clone the repo with:
git clone http://www.muchsync.org/muchsync.git
questions, comments, testimonials, bug reports, patches, and pull
requests to the author (preferably with the word “muchsync” in the email
subject). For pull requests, please spare me the trouble of navigating
any web sites and include a raw
git fetch command that
FETCH_HEAD point to whatever it is you would like me
muchsync is brought to you by David Mazières of the Stanford Secure Computer Systems group and Mail Avenger project.