NAME¶
OfflineIMAP Manual - Powerful IMAP/Maildir synchronization and reader support
SYNOPSIS¶
offlineimap [-h|--help]
offlineimap [OPTIONS]
-1
-P profiledir
-a accountlist
-c configfile
-d debugtype[,...]
-f foldername[,...]
-k [section:]option=value
-l filename
-o
-u interface
DESCRIPTION¶
Most configuration is done via the configuration file. Nevertheless, there are a
few command-line options that you may set for OfflineIMAP.
OPTIONS¶
- -1
- Disable most multithreading operations
Use solely a single-connection sync. This effectively sets the
maxsyncaccounts and all maxconnections configuration file variables to
1.
- -P
- profiledir
Sets OfflineIMAP into profile mode. The program will create profiledir (it
must not already exist). As it runs, Python profiling information about
each thread is logged into profiledir. Please note: This option is present
for debugging and optimization only, and should NOT be used unless you
have a specific reason to do so. It will significantly slow program
performance, may reduce reliability, and can generate huge amounts of
data. You must use the -1 option when you use -P.
- -a
- accountlist
Overrides the accounts option in the general section of the configuration
file. You might use this to exclude certain accounts, or to sync some
accounts that you normally prefer not to. Separate the accounts by commas,
and use no embedded spaces.
- -c
- configfile
Specifies a configuration file to use in lieu of the default,
~/.offlineimaprc.
- -d
- debugtype[,...]
Enables debugging for OfflineIMAP. This is useful if you are trying to track
down a malfunction or figure out what is going on under the hood. I
suggest that you use this with -1 to make the results more sensible.
-d requires one or more debugtypes, separated by commas. These define what
exactly will be debugged, and include three options: imap, maildir, and
thread. The imap option will enable IMAP protocol stream and parsing
debugging. Note that the output may contain passwords, so take care to
remove that from the debugging output before sending it to anyone else.
The maildir option will enable debugging for certain Maildir operations.
And thread will debug the threading model.
- -f
- foldername[,foldername]
Only sync the specified folders. The foldernames are the untranslated
foldernames. This command-line option overrides any folderfilter and
folderincludes options in the configuration file.
- -k
- [section:]option=value
Override configuration file option. If "section" is omitted, it
defaults to general. Any underscores "_" in the section name are
replaced with spaces: for instance, to override option autorefresh in the
"[Account Personal]" section in the config file one would use
"-k Account_Personal:autorefresh=30". You may give more than one
-k on the command line if you wish.
- -l
- filename
Enables logging to filename. This will log everything that goes to the
screen to the specified file. Additionally, if any debugging is specified
with -d, then debug messages will not go to the screen, but instead to the
logfile only.
- -o
- Run only once,
ignoring all autorefresh settings in the configuration file.
- -q
- Run only quick synchronizations.
Ignore any flag updates on IMAP servers.
-h|--help Show summary of options.
- -u
- interface
Specifies an alternative user interface module to use. This overrides the
default specified in the configuration file. The pre-defined options are
listed in the User Interfaces section. The interface name is case
insensitive.
USER INTERFACES¶
OfflineIMAP has various user interfaces that let you choose how the program
communicates information to you. The 'ui' option in the configuration file
specifies the user interface. The -u command-line option overrides the
configuration file setting. The available values for the configuration file or
command-line are described in this section.
Blinkenlights¶
Blinkenlights is an interface designed to be sleek, fun to watch, and
informative of the overall picture of what OfflineIMAP is doing. I consider it
to be the best general-purpose interface in OfflineIMAP.
Blinkenlights contains a row of "LEDs" with command buttons and a log.
The log shows more detail about what is happening and is color-coded to match
the color of the lights.
Each light in the Blinkenlights interface represents a thread of execution --
that is, a particular task that OfflineIMAP is performing right now. The
colors indicate what task the particular thread is performing, and are as
follows:
- •
- Black:
- indicates that this light's thread has terminated; it will
light up again later when new threads start up. So, black indicates no
activity.
- •
- Red (Meaning 1):
- is the color of the main program's thread, which basically
does nothing but monitor the others. It might remind you of HAL 9000 in
2001.
- •
- Gray:
- indicates that the thread is establishing a new connection
to the IMAP server.
- •
- Purple:
- is the color of an account synchronization thread that is
monitoring the progress of the folders in that account (not generating any
I/O).
- •
- Cyan:
- indicates that the thread is syncing a folder.
- •
- Green:
- means that a folder's message list is being loaded.
- •
- Blue:
- is the color of a message synchronization controller
thread.
- •
- Orange:
- indicates that an actual message is being copied. (We use
fuchsia for fake messages.)
- •
- Red (meaning 2):
- indicates that a message is being deleted.
- •
- Yellow / bright orange:
- indicates that message flags are being added.
- •
- Pink / bright red:
- indicates that message flags are being removed.
- •
- Red / Black Flashing:
- corresponds to the countdown timer that runs between
synchronizations.
The name of this interfaces derives from a bit of computer history. Eric
Raymond's Jargon File defines blinkenlights, in part, as:
Front-panel diagnostic lights on a computer, esp. a dinosaur. Now that dinosaurs
are rare, this term usually refers to status lights on a modem, network hub,
or the like.
This term derives from the last word of the famous blackletter-Gothic sign in
mangled pseudo-German that once graced about half the computer rooms in the
English-speaking world. One version ran in its entirety as follows:
ACHTUNG! ALLES LOOKENSPEEPERS!
Das computermachine ist nicht fuer gefingerpoken und mittengrabben.
Ist easy schnappen der springenwerk, blowenfusen und poppencorken
mit spitzensparken. Ist nicht fuer gewerken bei das dumpkopfen.
Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das
pockets muss; relaxen und watchen das blinkenlichten.
TTYUI¶
TTYUI interface is for people running in basic, non-color terminals. It prints
out basic status messages and is generally friendly to use on a console or
xterm.
Basic¶
Basic is designed for situations in which OfflineIMAP will be run non-attended
and the status of its execution will be logged. You might use it, for
instance, to have the system run automatically and e-mail you the results of
the synchronization. This user interface is not capable of reading a password
from the keyboard; account passwords must be specified using one of the
configuration file options.
Quiet¶
Quiet is designed for non-attended running in situations where normal status
messages are not desired. It will output nothing except errors and serious
warnings. Like Basic, this user interface is not capable of reading a password
from the keyboard; account passwords must be specified using one of the
configuration file options.
MachineUI¶
MachineUI generates output in a machine-parsable format. It is designed for
other programs that will interface to OfflineIMAP.
SIGNALS¶
OfflineImap listens to the unix signals SIGUSR1 and SIGUSR2.
If sent a SIGUSR1 it will abort any current (or next future) sleep of all
accounts that are configured to "autorefresh". In effect, this will
trigger a full sync of all accounts to be performed as soon as possible.
If sent a SIGUSR2, it will stop "autorefresh mode" for all accounts.
That is, accounts will abort any current sleep and will exit after a currently
running synchronization has finished. This signal can be used to gracefully
exit out of a running offlineimap "daemon".
KNOWN BUGS¶
- •
- SSL3 write pending:
- users enabling SSL may hit a bug about "SSL3 write
pending". If so, the account(s) will stay unsynchronised from the
time the bug appeared. Running OfflineIMAP again can help. We are still
working on this bug. Patches or detailed bug reports would be appreciated.
Please check you're running the last stable version and send us a report
to the mailing list including the full log.
- •
- IDLE support is incomplete and experimental. Bugs may be
encountered.
- •
- No hook exists for "run after an IDLE response".
Email will show up, but may not be processed until the next refresh
cycle.
- •
- nametrans may not be supported correctly.
- •
- IMAP IDLE <-> IMAP IDLE doesn't work yet.
- •
- IDLE may only work "once" per refresh. If you
encounter this bug, please send a report to the list!
- •
- Maildir support in Windows drive
Maildir uses colon caracter (:) in message file names. Colon is however
forbidden character in windows drives. There are several workarounds for that
situation:
- •
- Use maildir-windows-compatible = yes account OfflineIMAP
configuration.
- •
- That makes OfflineIMAP to use exclamation mark (!) instead
of colon for storing messages. Such files can be written to windows
partitions. But you will probably loose compatibility with other programs
trying to read the same Maildir.
- •
- Exclamation mark was choosed because of the note in
http://docs.python.org/library/mailbox.html
- •
- If you have some messages already stored without this
option, you will have to re-sync them again
- •
- Enable file name character translation in windows
registry (not tested)
- •
- Use cygwin managed mount (not tested)
- •
- not available anymore since cygwin 1.7
By default, we use fairly conservative settings that are good for syncing but
that might not be the best performing one. Once you got everything set up and
running, you might want to look into speeding up your synchronization. Here
are a couple of hints and tips on how to achieve this.
- 1.
- Use maxconnections > 1. By default we only use one
connection to an IMAP server. Using 2 or even 3 speeds things up
considerably in most cases. This setting goes into the [Repository XXX]
section.
- 2.
- Use folderfilters. The quickest sync is a sync that can
ignore some folders. I sort my inbox into monthly folders, and ignore
every folder that is more than 2-3 months old, this lets me only inspect a
fraction of my Mails on every sync. If you haven't done this yet, do it
:). See the folderfilter section the example offlineimap.conf.
- 3.
- The default status cache is a plain text file that will
write out the complete file for each single new message (or even changed
flag) to a temporary file. If you have plenty of files in a folder, this
is a few hundred kilo to megabytes for each mail and is bound to make
things slower. I recommend to use the sqlite backend for that. See the
status_backend = sqlite setting in the example offlineimap.conf. You will
need to have python-sqlite installed in order to use this. This will save
you plenty of disk activity. Do note that the sqlite backend is still
considered experimental as it has only been included recently (although a
loss of your status cache should not be a tragedy as that file can be
rebuild automatically)
- 4.
- Use quick sync. A regular sync will request all flags and
all UIDs of all mails in each folder which takes quite some time. A
'quick' sync only compares the number of messages in a folder on the IMAP
side (it will detect flag changes on the Maildir side of things though). A
quick sync on my smallish account will take 7 seconds rather than 40
seconds. Eg, I run a cron script that does a regular sync once a day, and
does quick syncs inbetween.
- 5.
- Turn off fsync. In the [general] section you can set fsync
to True or False. If you want to play 110% safe and wait for all
operations to hit the disk before continueing, you can set this to True.
If you set it to False, you lose some of that safety trading it for
speed.
SECURITY AND SSL¶
Some words on OfflineImap and its use of SSL/TLS. By default, we will connect
using any method that openssl supports, that is SSLv2, SSLv3, or TLSv1. Do
note that SSLv2 is notoriously insecure and deprecated. Unfortunately, python2
does not offer easy ways to disable SSLv2. It is recommended you test your
setup and make sure that the mail server does not use an SSLv2 connection. Use
e.g. "openssl s_client -host mail.server -port 443" to find out the
connection that is used by default.
Certificate checking¶
Unfortunately, by default we will not verify the certificate of an IMAP TLS/SSL
server we connect to, so connecting by SSL is no guarantee against
man-in-the-middle attacks. While verifying a server certificate fingerprint is
being planned, it is not implemented yet. There is currently only one safe way
to ensure that you connect to the correct server in an encrypted manner: You
can specify a 'sslcacertfile' setting in your repository section of
offlineimap.conf pointing to a file that contains (among others) a CA
Certificate in PEM format which validating your server certificate. In this
case, we will check that: 1) The server SSL certificate is validated by the CA
Certificate 2) The server host name matches the SSL certificate 3) The server
certificate is not past its expiration date. The FAQ contains an entry on how
to create your own certificate and CA certificate.
StartTLS¶
If you have not configured your account to connect via SSL anyway, OfflineImap
will still attempt to set up an SSL connection via the STARTTLS function, in
case the imap server supports it. Do note, that there is no certificate or
fingerprint checking involved at all, when using STARTTLS (the underlying
imaplib library does not support this yet). This means that you will be
protected against passively listening eavesdroppers and they will not be able
to see your password or email contents. However, this will not protect you
from active attacks, such as Man-In-The-Middle attacks which cause you to
connect to the wrong server and pretend to be your mail server. DO NOT RELY ON
STARTTLS AS A SAFE CONNECTION GUARANTEEING THE AUTHENTICITY OF YOUR IMAP
SERVER!
AUTHOR¶
John Goerzen <jgoerzen@complete.org>
COPYRIGHT¶
GPL v2
