How do I move my business email without losing anything?

The sequence matters because email delivery is controlled by a record at your domain registrar, and changing that record redirects future messages immediately while doing nothing about the ones already delivered. A business that switches and then attempts to move the archive is working against a live system rather than preparing in advance.

Start by establishing what you actually have. Every address on the domain, including aliases and forwarding rules nobody remembers creating. How much mail exists and how far back. Whether calendars and contacts are attached, since those migrate separately and are frequently forgotten until somebody notices an empty calendar.

Create the new mailboxes and verify the domain with the new provider before touching delivery. Verification is usually a record you add alongside the existing ones and it changes nothing about where mail arrives, which means it can be done safely in advance. Getting this out of the way removes the time pressure from the actual switch.

Migrate the existing mail while the old account is still receiving, using whichever import tool the new provider offers. Most support pulling directly from the old account, which is considerably more reliable than exporting and importing files. Run it, check that folders and dates survived, and expect it to take longer than estimated for a large archive.

Then change the delivery record and expect a period where mail arrives in both places. Propagation is not instant and different senders will resolve at different times, which is why leaving the old account active matters. Closing it immediately means messages sent during that window disappear rather than arriving late.

Watch for the things that break alongside email, since the address is used in more places than correspondence. Password resets, notifications from your tools, invoices from suppliers, and anything with a verification loop. Each of those continues working and some will need reconfiguring if you changed the address rather than only the provider.

Keep the old account for at least a month, and longer if the archive matters. Verify a sample of old messages in the new system before closing anything, because a migration that reported success can still have dropped attachments or folders, and discovering that after deletion is unrecoverable.

Tell the people who need to know, which is fewer than you think if the address itself is unchanged. A provider change is invisible to correspondents. An address change is not, and that requires notifying customers, suppliers, and anywhere the address is published.

Then check the authentication records once the switch is complete, since sending is a separate matter from receiving. A provider change frequently requires updating the records that authorise sending on your behalf, and getting those wrong means your mail arrives in spam folders while everything appears to work.

Do it during a quiet period rather than when convenient, since propagation produces a window where delivery is unpredictable and that window is worse during a busy week. A weekend or a slow stretch removes most of the risk from the one part of this you cannot control.

Test sending as well as receiving once the switch completes, since those are separate mechanisms and one can work while the other fails silently. Send to an address at a different provider and confirm it arrives in the inbox rather than the spam folder.

Keep a record of the old records before changing them, since reverting is only possible if somebody wrote down what was there.