How to Migrate Emails from One Host to Another (Complete 2026 Guide)

Switching email providers is one of those tasks that everyone dreads. Whether you are moving from a cheap shared host to Google Workspace, consolidating multiple mailboxes into one provider, or migrating an entire company from on-premise Exchange to the cloud, the stakes are high. Lose a single folder of important emails and you could lose invoices, contracts, or years of correspondence.

The good news is that in 2026, email migration is more straightforward than it has ever been. Modern tools handle the heavy lifting, and the protocols involved (IMAP, EWS, OAuth2) are well-documented and widely supported. This guide walks you through every approach, from do-it-yourself IMAP syncing to fully managed migration services.

Before You Start: Pre-Migration Checklist

Before you touch a single email, run through this checklist. Skipping these steps is the number-one cause of failed or incomplete migrations.

Method 1: IMAP-to-IMAP Migration

IMAP is the most universal email protocol. If both your source and destination servers support IMAP (and nearly all do), this is the most reliable migration path. The process connects to both servers simultaneously and copies messages folder by folder.

How It Works

1. A migration tool connects to the source server via IMAP using your credentials.
2. It reads the folder list and begins downloading messages.
3. It connects to the destination server via IMAP and uploads each message into the corresponding folder.
4. Metadata such as read/unread status, flags, and dates is preserved.

Tools for IMAP Migration

• imapsync: The gold standard open-source tool. Runs on Linux and macOS. Command-line only, but extremely reliable and well-documented.
• Email Migration Hub: Our web-based service uses the same underlying technology as imapsync but wraps it in a simple interface with live progress tracking. No command line needed.
• OfflineIMAP / mbsync: Lightweight Linux tools that sync IMAP mailboxes to local Maildir, which you can then upload to the new server.

Common IMAP Settings

Here are the IMAP settings for the most popular providers. You will need these when configuring the migration tool. Check our FAQ page for a more comprehensive list.

• Gmail: imap.gmail.com, port 993, SSL. Requires an app password if 2FA is enabled.
• Outlook / Hotmail: outlook.office365.com, port 993, SSL.
• Yahoo: imap.mail.yahoo.com, port 993, SSL. Requires an app password.
• iCloud: imap.mail.me.com, port 993, SSL. Requires an app-specific password.
• Zoho: imap.zoho.com, port 993, SSL.
• cPanel / Plesk: mail.yourdomain.com, port 993, SSL.

Method 2: Exchange / EWS Migration

If your source or destination is Microsoft Exchange (on-premise or hosted), you have an alternative to IMAP: Exchange Web Services (EWS). EWS provides richer access to mailbox data, including calendars, contacts, and tasks, not just emails.

When to Use EWS

• You need to migrate calendars and contacts alongside emails.
• The source server is Exchange 2010, 2013, 2016, 2019, or Exchange Online (Microsoft 365).
• IMAP is disabled or restricted on the Exchange server.

EWS Migration Steps

1. Obtain the EWS endpoint URL. For Microsoft 365, this is typically https://outlook.office365.com/EWS/Exchange.asmx.
2. Use a migration tool that supports EWS, such as our service or BitTitan MigrationWiz.
3. Authenticate using the user's credentials or an admin account with impersonation rights.
4. The tool reads and copies all mailbox items, including emails, calendar events, and contacts.

Method 3: OAuth2-Based Migration (Gmail, Outlook)

In 2026, both Google and Microsoft strongly prefer OAuth2 over traditional username-and-password authentication. OAuth2 lets you authorise a migration tool to access your mailbox without handing over your password. It is more secure and avoids issues with app passwords and two-factor authentication.

How OAuth2 Migration Works

1. You click an "Authorise" button in the migration tool.
2. You are redirected to Google or Microsoft's login page.
3. You grant the tool read access to your mailbox.
4. The tool receives a temporary access token and uses it to download your emails via IMAP or the provider's API.
5. The token expires after the migration completes, so no long-term access is retained.

Our Email Migration Hub service supports OAuth2 for both Gmail and Outlook. When you start a migration, you will see "Sign in with Google" and "Sign in with Microsoft" buttons that handle the entire OAuth2 flow automatically.

Method 4: Manual Migration via Desktop Client

If you only have a few hundred emails and prefer a hands-on approach, you can use a desktop email client like Thunderbird or Outlook to migrate manually. This method is slow and labour-intensive for large mailboxes, but it works in a pinch.

Steps for Thunderbird

1. Add both email accounts (source and destination) to Thunderbird.
2. Wait for both accounts to fully sync. This can take a while for large mailboxes.
3. Select all messages in a folder on the source account.
4. Right-click and choose "Copy To" then select the corresponding folder on the destination account.
5. Repeat for each folder.

Steps for Outlook Desktop

1. Add both accounts to Outlook.
2. Once both are synced, select messages and drag them from the source folders to the destination folders.
3. Alternatively, export the source mailbox to a PST file, then import the PST into the destination account.

Method 5: Using a Managed Migration Service

If you would rather not deal with server settings, protocols, and troubleshooting at all, a managed migration service handles everything for you. You provide access credentials, the service does the rest, and you receive a notification when it is complete.

What a Managed Service Does

• Connects to your source and destination mailboxes.
• Copies all emails with folder structure, read/unread status, and dates preserved.
• Handles throttling, timeouts, and retries automatically.
• Provides live progress tracking so you can see exactly what is happening.
• Sends you a completion report when done.

Why Choose Email Migration Hub

Our managed migration service starts at just GBP 29 for up to three mailboxes. That includes full IMAP-to-IMAP migration, OAuth2 support for Gmail and Outlook, folder structure preservation, and live progress tracking. We handle Gmail's throttling, Exchange's quirks, and everything in between.

For larger organisations, we offer packages for 6 and 12 mailboxes at discounted rates. Every migration runs on our UK-based servers, and your credentials are never stored. They are used only during the active migration session and discarded immediately after.

Post-Migration: What to Do After

Once your emails are safely on the new server, there are a few housekeeping tasks to complete:

1. Verify the Migration

Log into the destination mailbox via webmail and spot-check your folders. Look at the oldest and newest emails. Check that folder structure, read/unread status, and attachments are intact.

2. Update MX Records

Now is the time to change your domain's MX records to point at the new email provider. This tells the world to deliver new mail to your new server. DNS changes can take up to 48 hours to propagate globally, though most take effect within a few hours.

3. Keep the Old Account Active

Do not close the old email account immediately. Keep it active for at least two weeks to catch any stragglers, messages sent to the old server during DNS propagation. You can run a final sync after a week to pick up any late arrivals.

4. Update Email Clients

Update the server settings in Thunderbird, Outlook, Apple Mail, or any other client that connects to your email. Change the incoming (IMAP) and outgoing (SMTP) server addresses to the new provider's settings.

5. Test Sending and Receiving

Send a test email from an external account to your migrated address. Then reply to it. Confirm that both incoming and outgoing mail work correctly through the new server.

Common Mistakes to Avoid

• Changing MX records too early. This is the most common mistake. Always finish the migration before touching DNS.
• Forgetting app passwords. Gmail, Yahoo, and iCloud all require app-specific passwords if two-factor authentication is enabled. The migration will fail silently if you use your regular password.
• Ignoring mailbox quotas. If the destination mailbox has a storage limit, make sure it is large enough to hold all your migrated emails. Running out of space mid-migration causes partial copies.
• Migrating during peak hours. Large migrations generate significant IMAP traffic. If possible, start your migration in the evening or at the weekend when server load is lower.
• Not testing first. Before migrating 50 mailboxes, migrate one test account first. Verify everything works correctly before committing to the full batch.
• Using POP3 instead of IMAP. POP3 downloads emails and deletes them from the server. If you accidentally configure the migration tool with POP3 on the source, you could lose emails. Always use IMAP.