Migration
Exchange is running out.
What has to be decided now.
A sober assessment for everyone who runs a groupware server themselves or maintains one for customers — with dates, consequences and an honest statement of what AnnexGroup replaces and what it does not.
The dates
| What | When | What follows |
|---|---|---|
| Exchange Server 2016 and 2019 | 2025-10-14 | Support ended, no classic extended security update programme. The successor Exchange SE is a subscription; server and access licences went up by 10–20 %. |
| Kopano Groupware and Core | 2025-03-31 | No further development, subscriptions cannot be renewed. The successor “Kopano Cloud” is a hosting-only offering. The large DACH installed base from the Zarafa era is left without a successor. |
| Zimbra 9 OSE | 2025-06-30 | Community builds only. |
| EWS in Exchange Online | from 2026-10-01, finally 2027-04-01 | Microsoft is switching off Exchange Web Services. The successor, Microsoft Graph, exists exclusively in the cloud — there is no replacement for self-hosting. Integrations that run over EWS today have to be rebuilt. |
The last point is often overlooked. It affects not only those still on-premise, but every application that accesses mailboxes via EWS — archiving, signature management, fax gateways, CRM integrations, backup solutions. Whoever checks this only in autumn 2026 will have little time.
The three paths
Into the cloud
Microsoft 365 or Google Workspace. The least work, permanently the highest cost — $14 per user and month, with a documented tendency to increase. Plus the question of where the data lives and who can access it in doubt.
Exchange SE
Technically almost unchanged from 2019, but as a subscription. Familiar administration, familiar tools — and running costs where a perpetual licence used to be.
Switch within self-hosting
A different server in your own house. Requires a one-time migration effort, then control over cost, data and schedule. This is where AnnexGroup stands.
We do not claim the third path is right for everyone. If you want to move to the cloud anyway, you are better off there. AnnexGroup gets interesting when you want or need to stay self-hosted — for cost reasons, because of where the data sits, or because your customers want it that way.
What AnnexGroup covers — and what it does not
This table is the reason this page exists. It is meant to take the assessment off your plate of whether a test is even worth your time.
| Familiar from Exchange | In AnnexGroup |
|---|---|
| Mail via SMTP and IMAP | Yes, built in, with STARTTLS and DKIM signing |
| Calendar with invitations | Yes, iMIP for sending and receiving |
| Contacts | Yes, with vCard import and export |
| Tasks and notes | Yes |
| Public folders | As shared spaces — comparable in purpose, different in structure |
| Sharing and delegation | Yes, read and write between users |
| Web interface like Outlook Web | Yes, also installable as a web app |
| iPhone and Mac integration | Yes, via CalDAV and CardDAV |
| Out-of-office reply, rules | Yes, rules as Sieve filters |
| Spam and virus checking | Via Rspamd and ClamAV integration |
| MAPI / full Outlook integration | No. Outlook connects via IMAP and CalDAV. |
| ActiveSync | No. Mobile devices via IMAP and CalDAV/CardDAV. |
| EWS | No. Instead, its own REST API with OAuth2. |
| Multi-tenancy | Prepared in the data model, not yet in the interface — planned for version 2.0 |
| Automatic import of existing mailboxes | Not as a wizard yet. The IMAP copy route works; we describe it in the documentation. |
In short: If you need Outlook with full Exchange integration, AnnexGroup is the wrong choice. If you use mail, calendar, contacts and shared filing over standard protocols — and that is most smaller environments — you will find everything here again.
How a migration runs
- Set up in parallel. Install AnnexGroup on a separate machine, with a test domain. The existing server keeps running unchanged.
- Create the structure. Domains and users via the setup wizard or the command line.
- Copy the data. Transfer mailboxes over IMAP, calendars and contacts via ICS and vCard export. All of it without downtime in the running system.
- Test with a handful of people. Two weeks of real operation say more than any feature list.
- Switch over. Change the MX record. The old server stays as a way back until you are sure.
The 14-day trial period is sized so that steps 1 to 4 fit into it. If it is not enough, write to us — we extend it.
For IT service providers
If you maintain several customer environments: every installation needs its own licence, tiered by user count. Multi-customer tenant management does not exist yet — it is planned for version 2.0. Until then, the model is one installation per customer.
Tell us how many environments it would be. We will talk about terms instead of pointing you at a price list.