Package: rpatterson.mailsync
Integration between mswatch, OfflineIMAP, and Gnus for realtime mailContentsRequirementsInstallationTODOChangelog0.4 - 2009-06-280.3 - 2008-05-130.2 - 2008-05-070.1 - 2008-05-010.0 - BackstoryThis package provides some scripts that wrap parts of mswatch and
OfflineIMAP and integrate with Gnus to provide a local maildir that
is synchronized with a remote maildir as changes occur, instead of
polling on a regular basis.  This provides for near instant delivery
of new mail while also reducing resource utilization.  Integration
with the Emacs mail and newsreader, Gnus, is also provided in such a
way that your single threaded Emacs process is blocked much less as
changes occur to the maildirs.RequirementsmswatchOfflineIMAPGnusActually, they’re all kinda optional.  The OfflineIMAP sync wrapper
script can be used with mswatch without Gnus.  The Gnus checkers can
be used without OfflineIMAP.  For that matter, the OfflineIMAP sync
wrapper script can be used without mswatch, but why would you?  :)InstallationAll you need iseasy_install:$ easy_install rpatterson.mailsyncThe mailsync-gnus.el library will be installed in the site-lisp
directory in the egg.  To use the library, you’ll need to add this
path to your emacs load-path.  It should be something like the
following but be sure to substitute the question marks with the
appropriate values for your version of Python, the version of
rpatterson.mailsync, and your easy_install site-dirs:/usr/lib/python?.?/site-packages/rpatterson.mailsync-?-py?.?.egg/site-lisp/Alternatively, if you have a /usr/local/emacs/site-lisp directory, the
mailsync-gnus.el library can be installed into that directory if you
install rpatterson.mailsync from a source distribution.  You can still
use easy_install to get the source distribution:$ easy_install --editable --build-directory=/usr/local/src rpatterson.mailsync
$ cd /usr/local/src/rpatterson.mailsync/
$ python setup.py installOnce the library is on Emacs’ load-path, to use the
mailsync/gnus-check function, you’ll need to make sure it’s loaded in
your Emacs.  You can do this by adding the following to your .gnus.el:(load-library "mailsync-gnus")If you’ll be using mailsync_offlineimap to synchronize your mail,
start by configuring OfflineIMAP as per the OfflineIMAP
documentation.  Once OfflineIMAP is verified working, verify
mailsync_offlineimap by running it from the console.On any machine where you’ll be using the maildir watchers, either with
or without mswatch, see the mswatch documentation and verify that
watch_maildirs works.  Install rpatterson.mailsync wherever you want
to use mailsync_gnus_watch.  Run it from the console to test it.  It
should check all groups in Gnus and output a blank line when it’s
started up and then it should check any changed maildir folder groups
in Gnus when changed and then omit the folder name. Use
“mailsync_gnus_watch –help” to see what options are available to
modifying the watcher behavior.To use mswatch, see the mswatch documentation but base your
~/.mswatchrc on the following and see the “MAILSYNC:” comments for
what to change:# minimum time after first queued mailbox change to synchronization (default: 10s)
#base_delay 10

# minimum time between two syncs or failed attempts (default: 60s)
#inter_delay 60

# minimum time between two syncs or failed attempts for specific lists
#inter_delay 30 important_list
#inter_delay 600 high_volume_list another_list

# maximum waiting time between failed attempts (default: 600s)
#max_delay 600

# program (and arguments) to run to sync the mail stores (required)
# sync mswatch-sync

# MAILSYNC: use the following to have mswatch use your OfflineIMAP
# setup to sync folders on change.
sync mailsync_offlineimap

# prefix this string to sync's mailboxes;
#     useful as mbsync channel or OfflineIMAP account.
# the first string ("mydomain") is always prefixed
# the second string (":") is prefixed only when syncing a particular mailbox
mailbox_prefix foo :

# a store to watch, call it "local" (required)
store local
{
    # program (and args) that will monitor this store for changes (required)
    # see 'man watch_maildirs' to tell watch_maildirs where to find mail
    # watch watch_maildirs

    # MAILSYNC: use the following to have your local Gnus check
    # folders as they change, otherwise, just use the above.
    watch mailsync_gnus_watch
}

# the other store to watch, call it "mydomain" (required)
store foo.com
{
    # program (and args) that will monitor this store for changes (required).
    #
    # Uses ssh private/public keys to login without password prompting.
    # Uses ssh BatchMode so that 'mswatch' promptly detects disconnects.
    # Uses 'inputkill' to run 'watch_maildirs' so that 'watch_maildirs'
    # promptly exits if the connection dies.
        # watch ssh -o BatchMode=yes foo.com inputkill watch_maildirs

    # MAILSYNC: use the following to have your remote Gnus check
    # folders as they change, otherwise, just use the above.
    watch ssh -o BatchMode=yes foo.com inputkill mailsync_gnus_watch
}TODOUse optparse for syncersAdd built-in help and clearer option and argument handling for the
syncers using optparse.Use delay in watchers/checkersCurrently, the checkers run every time the watcher emits a folder
name.  Most maildir changes emit the same folder multiple times
resulting in the checker running reduntantly.  With mswatch, the
logic for coalescing events using a delay is in the mswatch process.
To address this problem, that logic would have to be extended to the
watchers.  This is another reason among many for reimplementing
mswatch.Invoke OfflineIMAP in the same processCurrently, mailsync invokes OfflineIMAP as a subprocess which is a
little wasteful given how heavy launching a python app can be.  I
briefly looked at the OfflineIMAP code to see if it could be easily
done but was disappointed.It would be great if any OfflineIMAP people want to show me how I
can do this.Long running syncersCurrently, mswatch invokes the sync process anew every time.  Pretty
much any sync process establishes one or more network connections.
There’s no need to do this every time.  Better to have a long
running sync process that mswatch can feed the folders to sync as
they require syncing.  Implementing this would require modifying or
reimplementing mswatch itself.  It would also require support in the
sync process.  Perhaps OfflineIMAP could be used as a library to
accomplish this.Ignore duplicate maildir notificationsAsdescribedon the mswatch page, every sync is redundantly issued
twice.  To address this would require modifying or reimplementing
mswatch itself.maildrop and gnus splitting?Maybe have maildrop directly invoke Gnus splitting and feed
incomming messages to be split at time of delivery.  This would
eliminate redundant syncs on the INBOX where gnus would otherwise
just immediately move the message into another folder.  This
approach is, however, probably way to heavy for a maildrop pipeline.An alternative approach would be to use a maildir (~/Incomming)
separate from the real INBOX maildir (~/Maildir) where mails would
first be delivered.  This incomming maildir could be monitored using
a checker/watcher whose only real purpose is to get gnus to check
the incomming maildir and split messages.  The split would then move
the message to the destination or fallback to the real INBOX maildir
which would in turn trigger any real watchers/checkers used by
mswatch.This approach requires no additional mailsync support.  It also
keeps maildrop job small and light, decoupling the gnus splitting
work from delivery.An advantage of either approach is that mail would be split on the
server even when the local mswatch wasn’t connected.  As it is now,
mail is only split when mswatch is running or if the Gnus running on
the server checks all mail periodically.Use GaminUse Gamin to provide compatibility across the file modification
services available.Changelog0.4 - 2009-06-28Propogate non-zero return codes from subprocesses so that mswatch
can know to restart things.Don’t check if the sync fails, allows mswatch to keep trying to sync
when offline without constantly making the checkers runAdd another syncer for offlineimap with a local-only gnus checkerTranslate Gmail and Gnus IMAP folder separators0.3 - 2008-05-13Clarify and correct documentation0.2 - 2008-05-07Fix handling of site-lisp for easy_install0.1 - 2008-05-01Initial release0.0 - BackstoryIt is amazing thatMUAs do indeed still suck.  In my case this is
exacerbated by a strong preference to use Gnus as my MUA.  Thunderbird
may be great, but since it lacks good integration with Emacs (and no,
emacsclient external editor is not enoug), it really doesn’t matter.I began by using nnimap to access dovecot on my server.  I was still a
Gnus newbie at that time and I ran into many problems with nnimap.  I
tried using the Gnus agent to address these but then my head and my
Emacs exploded in unison.As many others have before, I moved on to sync the ~/Maildir on my
server with a full local copy using OfflineIMAP.  Then I setup gnus on
my laptop to use nnimap talking to Dovecot running locally on my
laptop.  This worked fabulously with one exception, I had to choose
between how quickly new mail would show up and how much bandwidth
OfflineIMAP would use.  I’m pretty impatient about my email, so with a
sync frequency of every minute, I found that OfflineIMAP could easily
saturate what little bandwidth was available at a cafe or somesuch.
Lengthening the frequency only improved things slightly since every 5
minutes or what have you, my web browsing would still slow to a crawl.
I assume I was also slowing down everyone else, please don’t tell
them.  Still I used this approach for a year or more since I could
think of nothing better.Time went on and I used more and more of Gnus’ features.  I have a
beautiful BBDB fancy splitting setup.  I use automatic scoring which
is just a delight.  I agree that Gnus is much too hard to learn and
configure, but in all honesty, it could be even harder and I’d still
use Gnus.Later, with much more Gnus experience under my belt, I blew away my
.emacs and .gnus.el determined to use nnimap and the agent now that I
was more proficient.  I set it all up and it all seemed to work but as
time went on I kept running into more and more problems.  Over and
over again, the Group buffer would show inaccurate counts of new
messages or not show new messages at all.  I’d find that articles
hadn’t been downloaded after all so I wasn’t able to read them
offline.  I came to resemble a Skinarian pigeon, genuflecting before
Gnus in the face of chaos with mysterious combinations of “C-u g” and
“M-x gnus-agent-regenerate”.  In addition to those and many other
small annoyances, there was still the bandwidth vs check frequency
issue, only this time every time the mail would be checked my emacs
would block as well.Then I learned about IMAP IDLE and was beside myself with excitement.
Then I learned that neither OfflineIMAP nor Gnus nnimap supported it
and that Thunderbird did and I found myself seriously considering
switching.  Reluctance to leave Gnus, however, kept me googling for
some time and eventually I found mswatch.  Really a trio of three
utilities, mswatch uses Linux’s file modification notification system
(inotify or dnotify) to synchronize maildirs as needed.Initially, I tried mswatch with its intended sync program, mbsync, but
mbsync cannot sync nested IMAP folders.  The author of mswatch was
kind enough to document clearly the interfaces used for the separate
processes, so I set about writing a script that wraps OfflineIMAP to
provide the mswatch interface.  For the first time, I finally had a
mail setup that delivered new mail quickly and didn’t consume obscene
amounts of bandwidth.But wait, I use Gnus splitting with BBDB, so whenever mail arrived in
the INBOX on my server, it would be synced to my laptop which Gnus
would then split into its destination and then it would be synced back
to the server.  This little dance doubles the bandwidth consumption.
Furthermore, I’ve always wanted my BBDB splitting to be done on my
server for those times when I use Gnus in an SSH session or when I
access my mail from another IMAP client.  So I also wanted to notify
my gnus runnong on my server when when mail arrived.So then I set about writing a checker script that wraps the mswatch’s
watcher processes and uses “emacsclient –eval” to tell Gnus to check
the folder where a change has occurred.  On my server, this means the
mail will be split before notifying the mswatch process that a change
has occurred which means that mswatch will also synchronize the folder
the message was moved to.  No more round trip.  This also has the
added benefit of keeping Gnus up to date on all of my mail folders
without having to use gnus-demon to periodically check all folders.
All in all,muchfaster, very current information, and much less
interruptions.There are many things about this solution that are hackish and
inefficient so I’d say it’s somewhere between %75 and %80 there, as it
were.  Given, however, that no previous solution has even broken %50
I’m happy as a clam for now.