Developer(s)The Roundcube Team[1]
Initial release2008; 16 years ago (2008)
Stable release
1.6.6[2] Edit this on Wikidata / 20 January 2024
Written inPHP
Operating systemCross-platform
LicenseGPL-3.0-or-later with exceptions for skins and plugins [3] Edit this on Wikidata

Roundcube is a web-based IMAP email client. Roundcube's most prominent feature is the pervasive use of Ajax technology. Roundcube is free and open-source software subject to the terms of the GNU General Public License (GPL-3.0-or-later), with exceptions for skins and plugins.[3]


After about two years of development the first stable release of Roundcube was announced in early 2008.[4]

In November 2023, the open-source file hosting software suite Nextcloud announced its partnership with Roundcube.[5][6]

Security concerns

In 2023, a pro-Russia hacking group Winter Vivern[7] exploited a zero-day vulnerability in RoundCube to attack European government entities and a think tank, as reported by researchers from ESET.[8] This vulnerability was essentially a cross-site scripting error, and it was used to inject JavaScript into the Roundcube server application. Simply viewing a malicious email was sufficient to allow the attackers to run arbitrary JavaScript code in the Roundcube user's browser window, allowing them to access folders and emails in that user's account and send those emails to the attackers' servers.[9]

As of late 2023, the most recent eight releases (1.6.5, 1.5.6, 1.6.4, 1.5.5, 1.4.15, 1.5.4, 1.4.14 and 1.6.3) all contained XSS-related fixes.[10]


Roundcube is written in PHP and can be employed in conjunction with a LAMP stack, or any other operating systems that support PHP are supported as well. The web server needs access to the IMAP server hosting the email and to an SMTP server to be able to send messages.

Roundcube Webmail is designed to run on standard web servers such as Apache, LiteSpeed, Nginx, Lighttpd, Hiawatha or Cherokee in conjunction with a relational database engine. Supported databases are MySQL, PostgreSQL and SQLite. The user interface is rendered in XHTML and CSS and is fully customizable with skins.

Roundcube incorporates jQuery as part of its distribution, as well as other libraries such as GoogieSpell and TinyMCE.

Roundcube comes standard on CPanel this happened early 2008. Roundcube is the standard email service used by online hosting company's. The most used online hosting company that uses Roundcube is Frostbite Hosting .


Starting with version 0.3, Roundcube introduced a plug-in API which allows non-standard features to be added without the need to modify the source code. A variety of plug-ins are available from the Plugin Repository.

Project "Roundcube Next"

On 3 May 2015, Roundcube announced, in partnership with Kolab Systems AG, that they planned to completely rewrite Roundcube and create Roundcube Next. A crowdfunding campaign was set up to finance the project. The goal of $80,000 was reached on June 24.[11] The final amount raised was US$103,541.[12]

Roundcube Next was intended to include additional features like calendar, chat and file management. This was to be implemented using WebRTC and connectors from popular services like Dropbox and OwnCloud.

However, Kolab Systems and Roundcube stopped development on the project in 2016, with no information or refunds provided to project backers, leading to a failed crowdfund.[13] A Roundcube developer later claimed Roundcube had no ownership over the Roundcube Next campaign,[14] despite its public engagement and ownership on the crowdfund page.

Current features

Notable installations

Roundcube is used by a number of universities to provide email services to students and staff such as Sanger Institute Tata Institute of Social Sciences,[15] University of Florida,[16] Harvard University,[17] University of Utah,[18] University of Oregon,[19] Stevens Institute of Technology,[20] Norwegian University of Science and Technology,[21] the Technical University of Dortmund,[22] the University of Cambridge,[23] the Indian Institute of Technology, Delhi,[24] Indian Institute of Technology, Bombay,[25] Institute of Physics, Bhubaneswar, Indian Institute of Science Education and Research Kolkata and Department of Physics, Indian Institute of Technology Kanpur, Indian Institute of Technology, Madras,[26] University of Victoria, Bard College at Simon's Rock[27] and Bilkent University.[28]

In a 2009 interview, two of Roundcube's core developers noted that the largest deployment to that date that they were aware of was at the University of Michigan with 70,013 students.[29] Roundcube is also used in the Kolab Now service which supports its further development.

CPanel includes Roundcube, as a result of which many hosting companies around the world such as HostGator,[30] Media Temple, Gandi, OVH[31] and others use RoundCube. Roundcube Webmail IMAP client was also incorporated into epesiBIM (epesi Business Information Manager), a web-based, open source CRM-like application.

Apple's Mac OS X 10.7 Lion Server operating system provided Roundcube as the default webmail client in Mail Server.[32] In prior versions, SquirrelMail had been the default client.

In 2013, Iran's Ministry of ICT launched the national email service at which used Roundcube.[33] Synology Inc.'s DiskStation Manager (DSM) uses Roundcube for their Mail Station package. [34]

See also


  1. ^ "Dev_Members - Roundcube Webmail - Trac". Archived from the original on 2011-10-02. Retrieved 2011-09-19.
  2. ^ "Update 1.6.6 released". 20 January 2024. Retrieved 30 January 2024.
  3. ^ a b "Changeset 5787 - Roundcube Webmail". Archived from the original on 2012-04-26.
  4. ^ "RoundCube Webmail 0.1-stable released". 2008-03-04. Retrieved 2024-03-08.((cite web)): CS1 maint: date and year (link)
  5. ^ Korotaev, Mikhail (2023-11-29). "Open source email pioneer Roundcube joins the Nextcloud family". Nextcloud Blog. Retrieved 2023-12-02.
  6. ^ Rudra, Sourav (2023-12-01). "Open-Source Webmail Roundcube Joins Nextcloud". Retrieved 2023-12-02.
  7. ^
  8. ^
  9. ^
  10. ^ "Releases · roundcube/roundcubemail · GitHub". Retrieved 2023-12-26.
  11. ^ "Tweet from @roundcubenext".
  12. ^ "RoundCube-Next is Woefully Behind Schedule - Phoronix". Archived from the original on 2021-10-19. Retrieved 2021-10-19.
  13. ^ "In 2018, RoundCube Next Remains Dead In The Water - Phoronix". Archived from the original on 2021-10-19. Retrieved 2019-08-09.
  14. ^ "What about Roundcube Next? · Issue #6030 · roundcube/roundcubemail". GitHub. Archived from the original on 2021-10-19. Retrieved 2019-08-09.
  15. ^ "RoundCube Webmail". Archived from the original on 2021-10-19. Retrieved 2013-06-13.
  16. ^ "Development - University of Florida now hosting a RoundCube implementation". Archived from the original on 2020-11-29. Retrieved 2013-10-16.
  17. ^ "Welcome to RoundCube Webmail". Archived from the original on 2011-10-02. Retrieved 2011-09-19.
  18. ^ "University of Utah, College of Engineering Webmail". Archived from the original on 2021-07-11. Retrieved 2021-10-19.
  19. ^ "University of Oregon Webmail". Archived from the original on 2021-10-19. Retrieved 2021-10-19.
  20. ^ "MyMail - ITwiki". 2011-09-13. Archived from the original on 2012-02-03. Retrieved 2011-09-19.
  21. ^ "Alternative NTNU Student Webmail :: Welcome to Alternative NTNU Student Webmail". Archived from the original on 2021-10-19. Retrieved 2013-07-31.
  22. ^ "Roundcube Webmail :: Willkommen bei Roundcube Webmail". Retrieved 2022-05-06.
  23. ^ "Computing Service News: New Hermes Webmail". Computing Service, University of Cambridge. 2013-07-03. Archived from the original on July 6, 2013. Retrieved 2013-07-06.
  24. ^ "IITD Webmail :: Welcome to IITD Webmail". Archived from the original on 2021-10-19. Retrieved 2020-03-16.
  25. ^ "WebMail IITB :: Welcome to WebMail IITB". Archived from the original on 2021-10-19. Retrieved 2020-03-16.
  26. ^ Subhashis Banerjee (2011-09-04). "Roundcube webmail". Computer Services Centre, IIT Delhi. Archived from the original on 2021-03-05. Retrieved 2014-02-05.
  27. ^ "Bard College at Simon's Rock Webmail :: Welcome to Bard College at Simon's Rock Webmail". Retrieved 2021-11-25.
  28. ^ "Bilkent University Webmail :: Welcome to Bilkent University Webmail". 2022-06-08. Archived from the original on 2022-06-08. Retrieved 2022-08-19.
  29. ^ "Roundcube: the world's coolest Open Source webmail project? - Open For Business - Blogs - Technology Blog and Community from IT Experts -". 2009-11-20. Archived from the original on 2011-07-23. Retrieved 2011-09-19.
  30. ^ "Host Gator Adds RoundCube | WHTop News". Archived from the original on 2021-10-19. Retrieved 2020-03-22.
  31. ^ OVH. "Webmail: RoundCube Guide - OVH". Archived from the original on 2021-10-19. Retrieved 2017-02-07.
  32. ^ "OS X Lion Server - Technical Specifications". Apple. Archived from the original on October 6, 2011. Retrieved 2011-09-19.
  33. ^ "هشدار نویسنده نرم‌افزار ای‌میل ملی ایران درباره ضعف‌های امنیتی آن". 10 July 2013. Archived from the original on 2021-07-15. Retrieved 2021-10-19.
  34. ^ "Mail Station - Add-on Packages | Synology Inc". Archived from the original on 2020-11-11. Retrieved 2021-10-19.