This is the fear that stops people from switching hosts more than almost anything else. Years of email — client correspondence, invoices, important threads you’d never want to lose — sitting in a mailbox on your old host, and the idea of moving it feels like the single riskiest part of the whole process.
Done correctly, you lose nothing. Here’s exactly how.
The Core Idea: Overlap, Don’t Cut Over
The mistake that causes lost email is treating migration as a single moment — shut off the old account, turn on the new one, done. That approach has a gap: any email that arrives during the transition, or any message you haven’t yet copied over, falls through the crack.
The correct approach keeps both the old and new email accounts active simultaneously for a period of time, copies everything across using IMAP, and only decommissions the old account once you’ve confirmed everything transferred and DNS has fully propagated to the new server. There’s no moment where email can vanish, because both systems are live and either can receive mail during the transition.
Step One: Set Up the New Email Account First
Before touching anything on the old side, create your email account on the new server. In cPanel, go to Email → Email Accounts → Create, set up the account with the same address you’re currently using.
At this point, don’t change any DNS yet. Your domain’s MX records still point at your old host, so new email keeps arriving there uninterrupted. The new account exists and is ready to receive mail once you switch DNS later, but for now it’s just sitting there, empty.
Step Two: Copy Existing Mail Using an IMAP Client
The most reliable way to move existing email is to connect both accounts — old and new — in a single mail client and drag messages across. Thunderbird (free, available for Windows, Mac, and Linux) is the standard tool for this because it handles large IMAP transfers well and lets you work with two full accounts side by side.
- Install Thunderbird
- Add your old email account via IMAP (use your old host’s mail server settings)
- Add your new email account via IMAP (use
mail.yourdomain.comonce your new account is confirmed working) - Both accounts will appear as separate folder trees in the Thunderbird sidebar
- Select all folders in the old account (Inbox, Sent, and any custom folders)
- Drag and drop the messages into the corresponding folders in the new account
Thunderbird copies the messages across via IMAP — it doesn’t delete anything from the old account, so if something goes wrong midway, nothing is lost on either end. For large mailboxes, this can take a while. Let it run uninterrupted rather than closing the client partway through.
Tip: Do folders one at a time for large mailboxes rather than dragging everything at once. It’s easier to confirm each folder transferred completely, and if something interrupts the process, you know exactly where to resume.
Step Three: Verify the Copy
Before changing anything else, compare message counts between old and new for each folder. Right-click a folder in Thunderbird and check properties, or simply count visually for smaller folders. If the numbers match, the copy succeeded. If they don’t, redo that specific folder — don’t assume a small discrepancy will resolve itself.
The overlap window — both accounts live during migration
Step Four: Update Your MX Records
Once you’ve confirmed the copy is complete, update your domain’s MX records to point at the new server. This is what tells the internet to start delivering new incoming mail to the new mailbox instead of the old one.
If your domain and hosting are both moving to HostDango together, we handle this as part of setup. If you’re just moving email while keeping DNS elsewhere, update the MX records in whatever DNS management panel you use, pointing them at the mail server we provide.
DNS changes take time to propagate — usually a few hours, sometimes up to 48. During this window, some incoming mail may still route to the old server depending on which DNS servers a given sender’s mail system checks. This is exactly why you don’t decommission the old account yet.
Step Five: Wait, Then Verify Again
Give it 48 hours. Send test emails to yourself from an external account (Gmail is a good test) and confirm they’re arriving in the new mailbox. Check the old mailbox too — if new mail is still trickling in there, propagation isn’t complete yet or something in the sender’s system is caching old DNS.
Once you’ve confirmed new mail is consistently arriving at the new account and nothing new is showing up at the old one, you’re fully migrated.
Step Six: Only Now, Decommission the Old Account
Don’t delete or cancel the old email account until you’ve had at least a few days of confirmed clean delivery to the new one. There’s no rush — keeping the old account active and dormant for an extra week costs nothing and gives you a safety net if something unexpected turns up.
When you’re confident, cancel the old service and let the old mailbox go.
If You’re Also Moving to a New Device Setup
Once your email is fully migrated to the new server, your phone, laptop, and any other device connected via IMAP will need the new server settings. We covered exactly how to set this up across iPhone, Android, Mac, and Windows — the process is the same regardless of whether it’s a brand new account or a migrated one.
The short version: Create the new account first without touching DNS. Copy everything across using Thunderbird and IMAP while the old account keeps receiving mail. Verify the copy completed. Only then switch your MX records. Wait for propagation and verify again. Only decommission the old account once you’re certain nothing is still landing there. The overlap is what prevents loss — there’s never a moment where email has nowhere to go.
If any part of this feels daunting, open a support ticket before you start. We’d rather walk you through it than have you attempt it alone and worry the whole time.