Just to let you folks know:

https://www.sogo.nu/news/2025/sogo-v6-septembre.html

A lot of changes:

Techno and design

    SOGo 5 was using AngularJS and Objective-c. SOGo 6 now uses Python for its backend and Reactsjs for its frontend.
    The frontend and backend are now completely separated.
    The backend uses Flask and will serve a RESTful API.

Basic modules

    As for SOGo 5, SOGo 6 manages mails, calendars and address books

Mail interfacing

    SOGo 6 reads mail server (imap) and manages filtering (sieve) and outgoing mail (smtp).

Desktop software interfacing (outlook, thunderbird…)

    SOGo 6 still is a caldav/cardav server.
    For performance and troubleshooting reasons, support for ActiveSync will be removed and replaced by another Microsoft protocol: MAPI over http

User resource and SSO

    SOGo 6 reads the same user source, ldap or sql.
    SOGo 6 manages the same SSO: openid, saml2, cas.

Admin tool

    SOGo 5 was using a CLI command sogo-tool. SOGo 6 drops that to have a proper admin API.

New things

    SOGo 6 embarks a new process called Agent. It runs a tasks queues, using Celery and Redis, the new cache system. This agent will allow new features and tasks planification like : scheduling the sending of a mail or having a few seconds to cancel a sending.
    A brand new configuration system. Instead of a long sogo.conf file, SOGo 6 now has a proper admin interface to configure it.
    Multi-domains management has been reviewed to make it easy.

Migration from SOGO 5

Even though the SOGo 6 application is completely new, migration from SOGo 5 will be supported and will be carried out as smoothly as possible.

    The cache server Memcached is replaced by Redis
    SOGo’s database - for calendar, address books, user’s preferences… - has changed with SOGo 6. Table’s has been completely redone and PostgreSQL is required. Scripts to move data from your old database to your new database will be provided
    SOGo’s configuration has completely been redone. Only a few core parameters needs to be in ENV or a file. All the others one are stored in the database and are accessible through a brand new Admin interface. Except those core parameters, admin users will be able to import their old sogo.conf file on the admin interface and SOGo 6 will configure it automatically. Apart from this, all the others services stay as they are!

Greets