SOGo

Last reviewed Sep 13, 2026 · 803 words

The trap with SOGo is in its own description: it is a groupware server, and it does not move a single email. You bring the IMAP server, the SMTP relay, a PostgreSQL or MySQL database, memcached, an LDAP or SQL directory of users, and a reverse proxy; SOGo sits on top and turns that pile into something a phone or Outlook will treat as Exchange. The reason people put up with the pile is ActiveSync. Nothing else in open source lets a stock iPhone or Android mail app sync mail, calendar and contacts from one account setting with push, and for a company moving off Exchange that single feature decides the project.

Six services before the first login

SOGo itself is a GNUstep application written in Objective-C (a 2009 codebase, still actively maintained by Alinto) that listens on port 20000 as sogod. Around it you need, at minimum:

• An IMAP server for mailboxes. Dovecot is the assumed partner; SOGo stores nothing mail-related itself.
• An SMTP server or relay for outbound mail.
• PostgreSQL or MariaDB for user profiles, calendar and contact folders, and session state.
• memcached, which is not optional; SOGo refuses to be quick without it.
• A user source: LDAP (Active Directory works), or a SQL table with login and password columns.
• Apache or nginx in front, proxying /SOGo and /SOGo.woa/WebServerResources/ with TLS.

The configuration lives in one file, /etc/sogo/sogo.conf, in the OpenStep property-list format that nobody has written by hand since the 1990s. The keys that matter are SOGoProfileURL and OCSFolderInfoURL (database connection strings), SOGoIMAPServer, SOGoSMTPServer, SOGoUserSources, and SOGoMailDomain. Get those six right and the web interface works; everything else is tuning. Packages come from Alinto's repository for Debian, Ubuntu and RHEL, and there is a semi-official Docker image, but the cleanest way most people actually meet SOGo is inside mailcow, which bundles it with Dovecot, Postfix and Rspamd and hides all of the above. If you do not already have a mail server, start there rather than here.

ActiveSync works, and it will eat your worker processes

The sogo-activesync package adds the /Microsoft-Server-ActiveSync endpoint. Once a device is enrolled, it holds a long-poll "ping" connection open waiting for changes, and each open ping occupies one sogod worker for the duration. The default is 3 workers. Five phones and the web UI will hang. The fix is two lines:

WOWorkersCount = 10;
WOWatchDogRequestTimeout = 60;

Also raise the proxy's timeout to match (proxy_read_timeout 3540s in nginx is the number the SOGo docs use). Plan on roughly 1 worker per 2 active devices, and remember each worker is a full process with its own memory; the 1 GB baseline is realistic for 10 users, not 100. The official documentation has the full tuning table and I would read it before enrolling a second device.

CalDAV and CardDAV are the boring, excellent part

Thunderbird, Apple Calendar, DAVx5 on Android and Evolution all talk to SOGo with a single principal URL, shared calendars appear with the delegation rights you set in the web UI, and free/busy lookups work across users. Mail is where SOGo shows its age: the AJAX webmail is functional and fast enough, but it is the 2015 generation of web clients and looks it. Most deployments I have seen use SOGo for calendar and contacts, ActiveSync for phones, and a desktop IMAP client for anything serious. That is a fine outcome; it just is not the all-in-one screenshot on the homepage.

Nextcloud covers the same ground for a smaller team

If ActiveSync is not the requirement, Nextcloud with its Calendar, Contacts and Mail apps gives you CalDAV, CardDAV and webmail with a far larger community, a modern interface and one-container installs. The groupware category has the other contenders. SOGo wins on three things: native Outlook and phone sync, LDAP-first multi-tenant design that scales to thousands of accounts, and a maintainer who runs it commercially and ships security fixes quickly. It loses on everything a home user would notice on day one.

What I'd do

For a household or a team under 10 that is happy with DAV clients, Nextcloud and skip the six-service stack. For a business leaving Exchange with staff who expect their phones to just work, SOGo inside mailcow on a 4 GB box, WOWorkersCount set to 10 before the first device enrols, PostgreSQL rather than MySQL, and a test user on each phone platform for a week before migrating anyone's mail. My honest view of the whole mail-hosting question is in self-hosted email, honestly; SOGo does not change that calculus, it only makes the groupware half of it possible.