Exchange 2016 and 2019: regular support has ended
Exchange 2016 and 2019 have reached end of support. Your mailboxes stay on premises.
days since regular support ended
Regular support for Exchange Server 2016 and 2019 ended on 14 October 2025. Since then, security updates are only available through the paid ESU programme, which ends on 31 October 2026. Conbool Mail is an Exchange Server alternative that runs in your own data centre and uses your Active Directory.
July 2025
Exchange Server SE is released
The Subscription Edition replaces the previous versions. Licensing is by subscription.
14 October 2025
End of support for Exchange 2016 and 2019
Regular support ends for both versions on the same day.
31 October 2026
End of the ESU programme
The paid security updates run out. Microsoft has ruled out a further extension.
After that
No more updates
Exchange 2016 and 2019 will then receive no security updates, paid or otherwise.
End of support according to Microsoft Lifecycle, ESU period according to the Exchange team announcement of April 2026. Source: Microsoft Lifecycle
Decision
Exchange Server SE, Exchange Online or an alternative?
Each option is viable. They differ in where the mailboxes are held, how licensing works and who carries the operation.
Option 1
Exchange Server SE
You stay with Exchange on your own premises and move to the Subscription Edition.
- Where the mailboxes are held
- Your own data centre
- Licence
- Licences with active Software Assurance or a qualifying Microsoft 365 subscription
- Operation
- Windows Server, updates and hardening in your own hands
Option 2
Exchange Online
You give up your own server and move the mailboxes to Microsoft 365.
- Where the mailboxes are held
- Microsoft data centres
- Licence
- Per mailbox by subscription
- Operation
- Operated by Microsoft
Option 3
Conbool Mail
You replace Exchange and decide, according to your requirements, where the mailboxes are held.
- Where the mailboxes are held
- Your own data centre or with Conbool in Germany
- Licence
- Per mailbox
- Operation
- On Linux on your own premises, by us at Conbool
In your own data centre
A mail server that uses your Active Directory.
Conbool Mail runs on a Linux server in your network. Users sign in with their usual accounts.
Your network
Active Directory
Accounts and passwords stay where they are
Conbool Mail
Mailboxes, calendars, contacts and webmail
Active Directory- Webmail in the browser
- Outlook, Apple Mail, Thunderbird
- Smartphones through ActiveSync
Sign-in as usual
Users sign in with their Active Directory account. There is no second password.
Second factor for outside access
Access from outside your network can be tied to a second factor, access from inside cannot.
Data stays on premises
Mailbox content is held on your own infrastructure. This fits requirements that rule out a cloud.
What stays.
- Addresses and domainEvery address stays as it is. Nothing changes for senders and recipients.
- Active Directory accountsThe same users, the same passwords.
- The familiar clientsOutlook, Apple Mail, Thunderbird and the mail apps on the smartphone.
- Shared mailboxes, lists, roomsShared mailboxes, distribution lists, rooms and equipment remain available.
What changes.
- Outlook uses IMAP instead of MAPIEmail in Outlook runs over IMAP. Calendar and contacts are available in webmail, on the smartphone and via CalDAV and CardDAV.
- Administration in the portalYou manage mailboxes, access and rules in the Conbool portal instead of the Exchange admin center.
- Linux instead of Windows ServerThe mail server no longer needs a Windows Server or Exchange client access licences.
- Devices reconnect onceMail clients and smartphones receive the new settings, smartphones find them on their own via Autodiscover.
Migration
From Exchange Server to Conbool Mail.
The mailboxes move via IMAP or as a PST file, department by department if required. Exchange Server keeps running until the switch.
Questions about replacing Exchange Server
When did Exchange 2016 and Exchange 2019 reach end of life?
End of life, or EOL, was on 14 October 2025, the same day for both versions. Since then, security updates are only available through the paid ESU programme, which ends on 31 October 2026.
What is Exchange Server Subscription Edition?
Exchange Server Subscription Edition, or SE, has been the successor for on-premises operation since July 2025. It requires licences with active Software Assurance or a qualifying Microsoft 365 subscription.
Can I simply keep running Exchange 2019?
Technically the server keeps running. It only receives security updates through the paid ESU programme, and none at all after 31 October 2026. An internet-facing mail server without updates is a risk that cannot be carried for long.
Is there an Exchange Server alternative for our own data centre?
Yes. Conbool Mail can be operated on your own infrastructure and signs users in through the existing Active Directory. Webmail, mail clients via IMAP and smartphones through Exchange ActiveSync are available there.
Does Conbool Mail need a Windows Server?
No. Conbool Mail runs on a Linux server. Active Directory remains in place and continues to handle sign-in.
How do the mailboxes move from Exchange Server to Conbool Mail?
Via IMAP or as a PST file for each mailbox. Migration runs in the background, and Exchange Server stays in operation until the switch.
Replace Exchange Server in an orderly way.
We go through your environment with you and prepare the quote, for your own data centre or for operation with us.