How to Move Your Company Email to a New Provider Without Losing Messages

Companies change email providers for many reasons: slow service, mailboxes that are too small, a need for better collaboration tools, or simply clearer control over users. But the biggest worry is always the same: losing old messages that hold contracts, quotes and customer conversations, or having new mail stop arriving for days. The good news is that email migration can be smooth when it is planned in the right order. Here is how to do it, step by step.

Start by taking stock of what you actually have

Before moving anything, write down everything that depends on your company email. It is usually more than a set of staff mailboxes. A useful list includes:

• Individual mailboxes and their sizes, including any old archives.
• Shared mailboxes such as info and sales, and the groups that distribute messages to several people.
• Forwards and aliases, meaning addresses whose mail lands in another mailbox.
• Connected devices and apps: phones, desktop mail clients, and systems that send automatic mail such as invoices and notifications.
• Calendars and contacts, if you use them, because some migration methods move messages only.

This list protects you from a common surprise: everything works after the switch, then you find that the invoicing system or the website contact form was sending through the old server and nobody noticed.

Choose the migration method that fits your size

Your choice depends on how many users you have and which services you are moving between. The common approaches are:

1. IMAP migration: pulls messages from the old mailbox into the new one and works with most providers. Keep in mind that it normally moves messages only, so calendars and contacts may need a separate step.
2. Direct migration between compatible services: if both providers support a dedicated migration tool, it may move mail, calendars and contacts together.
3. Staged migration: you move groups of people at a time, which suits larger companies that don't want everyone affected at once.
4. All-at-once migration: suits small teams and is usually done over a weekend so work isn't disrupted.

If you are moving to Microsoft 365, most of these options are available, and the details depend on your current service. Ask your new provider which tool fits before you begin rather than assuming.

Back everything up before you touch anything

The most important rule of email migration is that old messages are never deleted from the first server until you are completely sure they arrived. So:

• Ask your current provider for a full copy of the mailboxes, or export them yourself from the mail client.
• Keep the copy somewhere separate from both the old and the new service.
• Don't cancel the old subscription on cutover day. Keep it for long enough to verify, because some providers delete mailboxes as soon as a subscription ends.

For backups in general, see our article on a backup strategy for companies.

Prepare your DNS records before the switch

DNS records decide where incoming mail for your domain goes. The key one is the MX record, which tells the world which server receives your mail. When you move, it must point to the new provider. Here is what is worth preparing:

• Lower the TTL on your mail records a day or two ahead. It controls how long other systems remember the old record, and the lower it is, the faster the change spreads.
• Prepare the new authentication records, such as SPF, DKIM and DMARC, as your new provider instructs, so your outgoing mail doesn't land in spam. We covered this in setting up business email on your own domain.
• Don't remove the old records too early: add what the new service needs first, then change the MX record at the planned time.

One important warning: if your domain has a strict DMARC policy, make sure the new provider is listed in your SPF record before the first message goes out from it, or your mail may be rejected.

Carry out the move in a clear order

Pick a quiet time, such as a weekend. A practical sequence looks like this:

1. Create the mailboxes and users in the new service, and test sign-in with a trial account.
2. Copy over the old messages. Large mailboxes can take time, so expect more than one pass.
3. Change the MX record to the new provider.
4. Tell staff when the change happens, how to sign in, and how to set up their phones.
5. Run a final copy to catch anything that reached the old mailbox while DNS was catching up.

Note that DNS changes don't reach everywhere at the same moment, so some mail may still land on the old server for a while after the switch. That is one more reason to keep the old service running rather than cancelling it straight away.

Check everything before you close the old service

Don't call the migration a success because the first message arrived. Run a proper check:

• Send mail from each key mailbox to several outside addresses and confirm it reaches the inbox, not spam.
• Send mail from outside to the new mailboxes, including shared ones and groups.
• Compare message counts in a sample of mailboxes, old against new.
• Review the systems that send automatic mail and update any that depend on the old server.
• Ask staff after a week about missing messages or folders.

Once you are confident, ask the old provider to close the account. Keep the backup you took for as long as your company's record-keeping policy requires.

Summary

Moving company email doesn't have to be a gamble. Take stock of what you have, choose the right method, keep a backup, prepare your DNS records ahead of time, and verify carefully before closing the old service. If you would like a specialist team to plan and carry out the move alongside the rest of your company email, the Role8 team will be glad to help.