OfflineIMAP is

IMAP In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

synchronization Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronou ...

utility software Utility software is software designed to help analyze, configure, optimize or maintain a computer. It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that benefit or ...

, capable of synchronizing mail on IMAP server with local Maildir folder or another server.

Description

The synchronization is performed bidirectionally between two endpoints ("Remote" and "Local" repositories). OfflineIMAP accesses mail servers only via

Internet Message Access Protocol In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

(

Post Office Protocol In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. POP version 3 (POP3) is the version in common use, and along with IMAP the most common ...

– another popular way to get mail from server – is not supported), it works faster (though it is sensitive to connection's latency) and supports more advanced features than most mail clients. The special mode for better handling the non-standard implementation of IMAP in

Gmail Gmail is a free email service provided by Google. As of 2019, it had 1.5 billion active users worldwide. A user typically accesses Gmail in a web browser or the official mobile app. Google also supports the use of email clients via the POP and ...

may optionally be enabled in a

configuration file In computing, configuration files (commonly known simply as config files) are files used to configure the parameters and initial settings for some computer programs. They are used for user applications, server processes and operating system ...

. When configured to store mail locally, OfflineIMAP uses the Maildir format. Unix mail boxes support may be added in the future, though currently it is not implemented.

Configuration

Several synchronizations account, each consisting of Remote and Local repositories, may be defined in configuration file. Each repository is then configured separately, allowing to specify credentials and access method.

Filtering and translation

OfflineIMAP is capable of filtering the folders of Remote repository, so that only partial synchronization would occur if needed. To use this capability one has to define the

mask A mask is an object normally worn on the face, typically for protection, disguise, performance, or entertainment and often they have been employed for rituals and rights. Masks have been used since antiquity for both ceremonial and pra ...

that would be matched against the list of folders with each synchronization. This is achieved by using Python's

lambda Lambda (}, ''lám(b)da'') is the 11th letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoenician Lamed . Lambda gave ri ...

capability; for example, to synchronize only "INBOX", "Sent Mail" and "Received" folders one should specify the following rule: folderfilter = lambda foldername: foldername in INBOX", "Sent Mail", "Received" Remaining folders' names may be altered (translated) using similar construct: nametrans = lambda foldername: re.sub( "^Sent$", "root/Sent", re.sub("^(\ .*ail\INBOX)", "root", foldername) ) This technique may also be used to synchronize the content of an IMAP server to the folder of another server.

Limitations

Each account has to use separate directory; otherwise the synchronization process may suffer from unexpected behavior or even data loss.

User interface

OfflineIMAP provides several

command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

s, including interactive color

curses A curse (also called an imprecation, malediction, execration, malison, anathema, or commination) is any expressed wish that some form of adversity or misfortune will befall or attach to one or more persons, a place, or an object. In particular ...

-based,

non-interactive Across the many fields concerned with interactivity, including information science, computer science, human-computer interaction, communication, and industrial design, there is little agreement over the meaning of the term "interactivity", but mos ...

console logging, and several yet less verbose modes. Tk-based

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, ins ...

is also available.

References