How to move email to a new provider without losing emails
By Ash, Founder, HosteazePublished 2 min read
The short answer
Set up your mailboxes at the new provider first, then copy your old emails across using its IMAP migration tool. Lower your MX record's TTL a day ahead, switch the MX records, and keep the old mailbox open for at least a few days, running a final copy to catch anything that arrived during the switch.
Moving email is like moving house. The danger isn't the big move; it's the post that keeps arriving at the old address for a week afterwards. Do things in the right order and you won't lose a single message, even with a busy inbox.
What do I need to sort out first?
- A list of every address in use, including aliases such as accounts@ and forwarding addresses that people forget about.
- The login details for each old mailbox, or admin access to the old provider.
- Access to your domain's DNS settings.
- A quiet day for the switch. We like a Friday afternoon for most businesses, because a hiccup over the weekend affects fewer customers.
Check how your old mail is stored, too. If the mailbox is IMAP, everything is on the server and can be copied. If it's POP3, some emails may only exist on the computer that downloaded them; see IMAP vs POP3.
Which way should I copy my old emails?
| Method | Good for | Watch out for |
|---|---|---|
| The new provider's migration tool | Most moves, and anything over a handful of mailboxes | Usually copies email only, not contacts or calendars |
| Dragging folders in a mail app | One or two small mailboxes | Slow with big folders, and easy to miss one |
| Export and import a file | Mail stored only on one computer | File formats differ between apps |
Both big suites have built-in tools. Microsoft 365's IMAP migration copies email folders but not contacts, calendar items or tasks, handles up to 500,000 items per mailbox and skips any single message over 35 MB. Google Workspace has a data import tool that pulls mail from an IMAP account.
How do I make the switch?
- Create every mailbox and alias at the new provider.
- A day ahead, lower the TTL on your MX records to 300 seconds, so the change reaches everyone within minutes.
- Run the first copy of old mail into the new mailboxes. This can take hours for a large mailbox, so start early.
- Change your MX records to the new provider's values and delete the old ones. Our guide to changing MX records has the details.
- Update your SPF record to include the new provider, and set up its DKIM record. Leave the old provider in SPF until you've stopped sending from it.
- Reconnect phones and computers to the new mailboxes.
- After three to five days, run the copy again. Many tools skip messages they've already copied, so this catches mail that arrived at the old provider during the switch.
- Once nothing new turns up at the old mailbox, cancel it.
What else can catch me out?
Website forms, printers and booking systems that send email through your old provider's server will stop working when you cancel it. Make a list and update each one. Also tidy your SPF record once the old service is gone, or you'll keep it listed for no reason; setting up SPF, DKIM and DMARC covers what it should contain.
If you're moving your email to Hosteaze, we offer free migration, so you can hand this list to us instead.
Step by step
1.Create the new mailboxes
Set up every address and alias at the new provider before changing anything else.
2.Lower the MX record TTL
A day before the switch, set your MX records' TTL to 300 seconds so the change spreads quickly.
3.Copy your old emails
Use the new provider's IMAP migration or import tool to copy every folder from the old mailbox.
4.Switch the MX records
Replace the old MX records with the new provider's, and update SPF and DKIM for the new service.
5.Run a final copy and keep the old mailbox
Wait a few days, run the migration again to catch late arrivals, then reconnect devices and close the old account.
Frequently asked questions
Will I miss emails during the switch?
Not if you keep the old mailbox running. While the MX change spreads, some senders still deliver to the old provider. A final copy a few days later picks those messages up.
Do contacts and calendars move too?
Not with an IMAP migration, which only copies email. Export contacts and calendars from the old service, usually as CSV or vCard files and ICS files, and import them at the new one.
My old email was set up with POP3. Is that a problem?
It can be. POP3 usually downloads messages and removes them from the server, so older emails may only exist on one computer. Add that computer's mail app to the new account and drag the folders across, or export them from the app.
