SquirrelMail
Encyclopedia
SquirrelMail is an Open Source
project that provides both a web-based email
application and an IMAP proxy server
.
The webmail portion of the project was started by Nathan and Luke Ehresman in 1999 and is written in the PHP
scripting language. It can be installed on almost all web server
s as long as PHP is present and the web server has access to an IMAP and SMTP server.
SquirrelMail webmail outputs valid HTML
4.0 for its presentation, making it compatible with a majority of current web browser
s. SquirrelMail webmail uses a plugin architecture to accommodate additional features around the core application, and over 200 plugins are available on the SquirrelMail website
The SquirrelMail IMAP proxy server product was created in 2002 by Dave McMurtrie while at the University of Pittsburgh
(where it was named "up-imapproxy", although it has become more commonly known as "imapproxy") and adopted by the SquirrelMail team in 2010. It is written in C
and is primarily made to provide stateful
connections for stateless webmail client software to an IMAP server, thus avoiding new IMAP logins for every client action and in some cases significantly improving webmail performance.
Licensed under the GNU General Public License
, both SquirrelMail products are free software
. The webmail product is currently available in over 50 languages. SquirrelMail webmail is included in the repositories of many major GNU/Linux distributions
and is independently downloaded by tens of thousands of people every month.
, FreeBSD
, Mac OS X
and the server variants of Microsoft Windows
.
SquirrelMail IMAP Proxy compiles on most flavors of Unix
, and can generally be used on the same platforms as the webmail product can be with the exception of Microsoft Windows
, unless used in a Cygwin
or similar environment.
. There are over 200 third-party plugins available for download from the SquirrelMail website, and SquirrelMail ships with several "standard" or "core" plugins, allowing an administrator to add:
Examples of functionalities added by various third-party plugins include:
.
HEC Montréal deployed SquirrelMail as part of a comprehensive webmail solution, to support thousands of users.
Squirrelmail is the web mail application of the University of Bristol
, Keele University
, the Indian Institute of Technology Bombay
, (particularly the CSE department) Indian Institute of Technology Kanpur
, Carnegie Mellon University
, Dokuz Eylül University
, Sharif University of Technology
, as well as other universities.
is available for reporting bugs
or submitting patches
. For administrators or companies official and third party commercial support is available.
Apple ships SquirrelMail as their supported web mail solution in Mac OS X Server
.
attack. The "upgrade" page has been hosted on various compromised systems across the Internet and the attack has continued at least through July 2009 (sample).
As a result, the SquirrelMail team skipped version 1.4.14 and its next release after 1.4.13 was 1.4.15.
This versioning tactic was of limited effectiveness, as later phish runs referenced 1.4.15 instead of 1.4.14.
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
project that provides both a web-based email
Web-based email
The term Webmail is used to describe two things. One use of the word is to describe a Webmail client: an email client implemented as a web application accessed via a web browser. This article focuses in this use of the term...
application and an IMAP proxy server
Proxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
.
The webmail portion of the project was started by Nathan and Luke Ehresman in 1999 and is written in the PHP
PHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
scripting language. It can be installed on almost all web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
s as long as PHP is present and the web server has access to an IMAP and SMTP server.
SquirrelMail webmail outputs valid HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
4.0 for its presentation, making it compatible with a majority of current web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
s. SquirrelMail webmail uses a plugin architecture to accommodate additional features around the core application, and over 200 plugins are available on the SquirrelMail website
The SquirrelMail IMAP proxy server product was created in 2002 by Dave McMurtrie while at the University of Pittsburgh
University of Pittsburgh
The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...
(where it was named "up-imapproxy", although it has become more commonly known as "imapproxy") and adopted by the SquirrelMail team in 2010. It is written in C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and is primarily made to provide stateful
State (computer science)
In computer science and automata theory, a state is a unique configuration of information in a program or machine. It is a concept that occasionally extends into some forms of systems programming such as lexers and parsers....
connections for stateless webmail client software to an IMAP server, thus avoiding new IMAP logins for every client action and in some cases significantly improving webmail performance.
Licensed under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
, both SquirrelMail products are free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
. The webmail product is currently available in over 50 languages. SquirrelMail webmail is included in the repositories of many major GNU/Linux distributions
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...
and is independently downloaded by tens of thousands of people every month.
Platforms
SquirrelMail webmail is available for any platform supporting PHP. Most commonly used platforms include LinuxLinux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
, Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
and the server variants of Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
.
SquirrelMail IMAP Proxy compiles on most flavors of Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
, and can generally be used on the same platforms as the webmail product can be with the exception of Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, unless used in a Cygwin
Cygwin
Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment...
or similar environment.
Future development
New releases of the stable SquirrelMail product are made as needed to address any bugs or security issues which may be discovered. Development of new features and enhancements is concentrated on the development product, which, in time, will itself become the stable product. The SquirrelMail 1.5 Roadmap outlines some of the features slated for the next developmental release, including:- A templating system
- A RPCRemote procedure callIn computer science, a remote procedure call is an inter-process communication that allows a computer program to cause a subroutine or procedure to execute in another address space without the programmer explicitly coding the details for this remote interaction...
interface for use by other applications as well as AJAXAjax- Mythology :* Ajax , son of Telamon, ruler of Salamis and a hero in the Trojan War, also known as "Ajax the Great"* Ajax the Lesser, son of Oileus, ruler of Locris and the leader of the Locrian contingent during the Trojan War.- People :...
-enabled SquirrelMail template sets (skins) - A new initialization system
- Faster login times due to improved message header caching
- Security enhancements, such as HTTPOnly cookiesHTTP cookieA cookie, also known as an HTTP cookie, web cookie, or browser cookie, is used for an origin website to send state information to a user's browser and for the browser to return the state information to the origin site...
- Improved usability/accessibilityWeb accessibilityWeb accessibility refers to the inclusive practice of making websites usable by people of all abilities and disabilities. When sites are correctly designed, developed and edited, all users can have equal access to information and functionality...
Plugins
The SquirrelMail webmail client itself is a complete webmail system, but extra features are available in the form of plugins. A plugin allows non-standard features to be added to SquirrelMail, often without the need to modify the source codeSource code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
. There are over 200 third-party plugins available for download from the SquirrelMail website, and SquirrelMail ships with several "standard" or "core" plugins, allowing an administrator to add:
- Spell checking (squirrelspell)
- Mail filters (filters)
- Web-based administration of SquirrelMail (administrator)
- A calendar (calendar)
- An interface to submit bug reports semi-automatically (bug_report)
Examples of functionalities added by various third-party plugins include:
- Address book/contact grouping and other address book expansions
- Monitoring and security tools to track usage, fight attackers and improve security
- Password change
- Single sign-onSingle sign-onSingle sign-on is a property of access control of multiple related, but independent software systems. With this property a user logs in once and gains access to all systems without being prompted to log in again at each of them...
support, one-time passwordsOne-time passwordA one-time password is a password that is valid for only one login session or transaction. OTPs avoid a number of shortcomings that are associated with traditional passwords. The most important shortcoming that is addressed by OTPs is that, in contrast to static passwords, they are not vulnerable...
, login aliases and several other credential manipulations and lookups - Quota reporting
- Rich text (HTML) email composition and display
- User-configurable front-ends for autorespondersAutoresponderAn autoresponder is a computer program that automatically answers e-mail sent to it. They can be very simple or quite complex.The first autoresponders were created within mail transfer agents that found they could not deliver an e-mail to a given address. These create bounce messages such as "your...
, spam filtering systems such as SpamAssassinSpamAssassinSpamAssassin is a computer program released under the Apache License 2.0 used for e-mail spam filtering based on content-matching rules. It is now part of the Apache Foundation....
and server-side mail filters - Weather reporting
- User account control panel
Internationalization
SquirrelMail webmail has been translated into over 50 languages including Arabic, Chinese, French, German, and Spanish.Notable installations
SquirrelMail has been implemented as the official email system of the Prime Minister's Office of the Republic of India for its security advantages over Microsoft's Outlook ExpressOutlook Express
Outlook Express is an email and news client that is included with Internet Explorer versions 4.0 through 6.0. As such, it is also bundled with several versions of Microsoft Windows, from Windows 98 to Windows Server 2003, and is available for Windows 3.x, Windows NT 3.51, Windows 95 and Mac OS 9...
.
HEC Montréal deployed SquirrelMail as part of a comprehensive webmail solution, to support thousands of users.
Squirrelmail is the web mail application of the University of Bristol
University of Bristol
The University of Bristol is a public research university located in Bristol, United Kingdom. One of the so-called "red brick" universities, it received its Royal Charter in 1909, although its predecessor institution, University College, Bristol, had been in existence since 1876.The University is...
, Keele University
Keele University
Keele University is a campus university near Newcastle-under-Lyme in Staffordshire, England. Founded in 1949 as an experimental college dedicated to a broad curriculum and interdisciplinary study, Keele is most notable for pioneering the dual honours degree in Britain...
, the Indian Institute of Technology Bombay
Indian Institute of Technology Bombay
The Indian Institute of Technology Bombay , popularly known as IIT Bombay or IITB, is a public research university located in Powai, Mumbai...
, (particularly the CSE department) Indian Institute of Technology Kanpur
Indian Institute of Technology Kanpur
The Indian Institute of Technology Kanpur is a Central deemed University located in Uttar Pradesh, about 15 km north-west of the city of Kanpur in the Kalyanpur suburb....
, Carnegie Mellon University
Carnegie Mellon University
Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
, Dokuz Eylül University
Dokuz Eylül University
Dokuz Eylül University is one of the preeminent universities in Turkey. It is located in İzmir, Turkey. It was founded in 1982 and is organized in 10 schools...
, Sharif University of Technology
Sharif University of Technology
Sharif University of Technology is a university of higher education in technology, engineering and physical sciences in Tehran. Sharif University of Technology is one of the most prestigious universities in the country, and is considered Iran's MIT...
, as well as other universities.
Support
There are several mailing lists available. Several of the developers are available for live chat on IRC. A bug tracking systemBug tracking system
A bug tracking system is a software application that is designed to help quality assurance and programmers keep track of reported software bugs in their work. It may be regarded as a type of issue tracking system....
is available for reporting bugs
Software bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...
or submitting patches
Patch (computing)
A patch is a piece of software designed to fix problems with, or update a computer program or its supporting data. This includes fixing security vulnerabilities and other bugs, and improving the usability or performance...
. For administrators or companies official and third party commercial support is available.
Apple ships SquirrelMail as their supported web mail solution in Mac OS X Server
Mac OS X Server
Mac OS X Server is a Unix server operating system from Apple Inc. The server edition of Mac OS X is architecturally identical to its desktop counterpart, except that it includes work group management and administration software tools...
.
Skipped 1.4.14 version
On May 27, 2008 the SquirrelMail Team announced that, while the latest released version of their software was 1.4.13, a spammer was sending unsolicited email messages to various recipients about a 1.4.14-rc1 release candidate version which didn't really exist. The messages (usually titled "Internet Users Email Upgrade (IUEU)") urged recipients to upgrade immediately (because of supposed security issues) and contained a web link for users to do so. However, that web link pointed to a page where the spammer was collecting email addresses and passwords. Beside the fact that end users are not responsible for upgrading such software, that the "upgrade" page was merely a mock SquirrelMail login page made it clear that this was a PhishingPhishing
Phishing is a way of attempting to acquire information such as usernames, passwords, and credit card details by masquerading as a trustworthy entity in an electronic communication. Communications purporting to be from popular social web sites, auction sites, online payment processors or IT...
attack. The "upgrade" page has been hosted on various compromised systems across the Internet and the attack has continued at least through July 2009 (sample).
As a result, the SquirrelMail team skipped version 1.4.14 and its next release after 1.4.13 was 1.4.15.
This versioning tactic was of limited effectiveness, as later phish runs referenced 1.4.15 instead of 1.4.14.
See also
- Internet Messaging ProgramInternet Messaging ProgramThe Internet Messaging Program or IMP is an open source PHP-based webmail client for IMAP. IMP is a component of the Horde project.It is included with cPanel and Plesk installations as a webmail client...
- RoundCubeRoundCubeRoundcube is a web-based IMAP email client written in the PHP programming language. Roundcube's most prominent feature is the pervasive use of Ajax technology to present a more fluid and responsive user interface than that of traditional webmail clients...
- Atmail
- Comparison of e-mail clientsComparison of e-mail clientsThe following tables compare general and technical features of a number of email client programs. Please see the individual products articles for further information. This article is not all-inclusive or necessarily up to date.-General:...