Email is the most sensitive part of leaving Microsoft 365. A lost message or one sent to spam is noticed the same day. We move your mailboxes, calendars and contacts to email hosted in Europe or to a free software mail server, with the same addresses.
Zimbra at OVHcloud or Infomaniak. The provider runs the servers, backups and deliverability, for a monthly fee per mailbox.
Mailcow, Stalwart or SOGo, on servers rented in your name. It needs an operations team or a managed services contract to watch IP reputation and blocklists.
For a small or medium organisation, we recommend hosted email.
With Zimbra at OVHcloud, the provider takes care of these tasks. We set up the domain (SPF, DKIM, DMARC), copy the mailboxes and train users.
Hosted email suits SMEs, non-profits and local authorities with no on-call team. A free software mail server suits organisations with an operations team, or a managed services contract with us, that want to keep mailboxes on their own servers.
For a small organisation, email hosted by a French provider is often enough. OVHcloud offers two Zimbra plans.
| Plan | Storage per mailbox | Calendars and contacts | Phones (ActiveSync) |
|---|---|---|---|
| Zimbra Starter | 15 GB | Yes, over CalDAV and CardDAV | No |
| Zimbra Pro | 50 GB | Yes | Yes |
Plans read on ovhcloud.com on 17 October 2026. Both include webmail, antispam, antivirus and a daily backup. Infomaniak, in Switzerland, also offers hosted email with calendars and contacts.
Everyone keeps their email address.
Calendars and contacts stay in the mail system (Zimbra, SOGo) or move to Nextcloud. They sync with phones and with Thunderbird, over CalDAV and CardDAV.
Microsoft announced it will progressively block Exchange Web Services (EWS) in Exchange Online from October 2026, in favour of Microsoft Graph. Software reading mailboxes through EWS (archiving, sync, business applications) needs to be listed, whether or not you stay on Microsoft 365.
Yes. The domain name stays yours and the mailboxes are recreated at the new provider, with existing messages and folders.
Outlook reads and sends email over IMAP with most providers. For shared calendars, webmail or Thunderbird work better.
We set up SPF, DKIM and DMARC before the switch and check delivery to Gmail and Outlook.com afterwards.
No, they are independent. Nextcloud's Mail app can show your messages inside Nextcloud, but it is only a client.
Yes for a French municipality under 3,500 inhabitants or an inter-municipal body under 15,000, through the ANCT's Suite territoriale. Messages is at version 0.10 (September 2026) and cannot be read in Thunderbird or Outlook. For other organisations, we recommend hosted email.
They are rented in France in your organisation's name, and your data stays there.
Audit reports and operations documentation belong to you, whether or not you keep working with us.
The person who answers you is the one who works on your servers and desktops.
Tell us which email system you use and how many mailboxes you have. An engineer will reply by email.