SOGo

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What SOGo is

SOGo is a free, open-source, self-hosted groupware server for sharing organizational email, calendars, and address books. Its AJAX web interface provides messaging and calendar access, while CalDAV, CardDAV, IMAP, SMTP, and Microsoft Exchange ActiveSync connect clients and synchronize information. Listed clients include Mozilla Thunderbird, Microsoft Outlook, Apple Calendar and Contacts, and ActiveSync-compatible devices. People can share mail, calendars, and address books with per-person or per-group rights, delegate mailbox access, and delegate invitations. Mail functions include multiple IMAP accounts, server-side filtering, custom identities, forwarding, and auto-replies. Security options include authenticator-app two-factor authentication, password policies, S/MIME signing and encryption, and single sign-on through CAS, WebAuth, or Kerberos. SOGo can reuse existing IMAP, SMTP, database, and LDAP services such as Active Directory, OpenLDAP, MySQL, and PostgreSQL. Linux packages and a virtual appliance support deployment or testing. The maker says its horizontally expandable architecture can serve from a handful to hundreds of thousands of users.

Who it suits

It suits organizations that can self-host shared mail, calendar, and address-book services and need open protocols or delegated access. It is also relevant to teams using the listed desktop, mobile, and web clients.

What it does well

Free and open-source under GNU GPL/LGPL
Supports shared mail, calendars, and address books
Offers multiple authentication and encryption options
Works with existing IMAP, SMTP, database, and LDAP services
Supports listed Thunderbird, Outlook, Apple, and ActiveSync clients

What to know first

Requires self-hosted deployment
Premium support excludes several service areas
Community support has no official release access
Paid support contracts are prepaid yearly

Plans

Plan	Billed and limits	Price
SOGo	Free and open-source groupware server · GNU GPL/LGPL v2 and above	Free
Community support	Mailing list · FAQ · Documentation · No official release access	Free
Silver	One-year prepaid contract · 10 incidents · 4-business-hour acknowledgement · Release access · Bug fixes for current version · Portal tickets and live Visio	$1,500 a year
Sponsorship	One-year prepaid contract · Release access · Nightly builds · Support via mailing list, FAQ, and documentation · Unused tickets are not extended	$500 a year
Gold	One-year prepaid contract · 30 incidents · 2-hour acknowledgement · 4 consulting hours · Priority bug fixes · Portal tickets and live Visio	$5,000 a year
Platinum	One-year prepaid contract · 50 incidents · 2-hour acknowledgement · 6 consulting hours · Priority bug fixes · Portal tickets and live Visio	$7,500 a year

As sogo.nu lists them, read 12 Oct 2026. The maker's own page has the final word.

Verdict

SOGo provides a broad, protocol-based groupware server with sharing, delegation, and security controls. Its self-hosted model offers flexibility, but deployment and support responsibilities remain important considerations.

Facts from SOGo's own pages

App coverage: all · sogo.nu, 21 Sept 2026
Backends: SOGo can reuse existing IMAP, SMTP, database, and LDAP services, including Active Directory, OpenLDAP, MySQL, and PostgreSQL. · sogo.nu, 12 Oct 2026
Calendar tools: Yes · sogo.nu, 21 Sept 2026
Client integrations: The maker lists Mozilla Thunderbird, Microsoft Outlook, Apple Calendar and Contacts, and ActiveSync-compatible devices as supported clients. · sogo.nu, 12 Oct 2026
Collaboration: Users can share mail, calendars, and address books with per-person or per-group rights, and delegate mailbox access or invitations. · sogo.nu, 12 Oct 2026
Current release: The download page lists SOGo 5.12.11, released September 14, 2026. · sogo.nu, 12 Oct 2026
Deployment: SOGo is self-hosted software with packages for Linux distributions and a Zero Effort Groupware virtual appliance for testing. · sogo.nu, 12 Oct 2026
Free plan: Yes · sogo.nu, 21 Sept 2026
Mail tools: Features include multiple IMAP accounts, server-side mail filtering, custom identities, forwarding, and auto-replies. · sogo.nu, 12 Oct 2026
Open protocols: SOGo uses CalDAV, CardDAV, IMAP, SMTP, and Microsoft Exchange ActiveSync to connect clients and synchronize information. · sogo.nu, 12 Oct 2026
Product: SOGo is an open-source groupware server for sharing organizational email, calendars, and address books. · sogo.nu, 12 Oct 2026
Scale: The maker says SOGo can scale from a handful to hundreds of thousands of users through a horizontally expandable architecture. · sogo.nu, 12 Oct 2026
Security: Listed security features include authenticator-app two-factor authentication, password policies, S/MIME signing and encryption, and single sign-on via CAS, WebAuth, or Kerberos. · sogo.nu, 12 Oct 2026
Support: Community help is available through a mailing list, while Alinto offers commercial support packages and documentation is provided online. · sogo.nu, 12 Oct 2026
Support limits: Premium support excludes component installation, custom development, preventive monitoring, training, and documentation, and it does not commit to issue resolution times. · sogo.nu, 12 Oct 2026
Web interface: SOGo provides an AJAX-based web interface for accessing messaging and calendaring data. · sogo.nu, 12 Oct 2026

Where SOGo stands on Freedom251

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