Overview
The Imapsync Online Tool available at Imapsync Online Interface allows users to migrate or synchronize email mailboxes between two IMAP servers directly from a web browser. It is the web-based version of imapsync, a well-known command-line tool used for migrating or backing up IMAP email accounts.
This tool is useful when moving email accounts between hosting providers, mail servers, or services such as cPanel, Gmail, or other IMAP-compatible servers.
What is Imapsync?
Imapsync is an email migration tool designed to copy or synchronize messages from one IMAP mailbox to another. It supports incremental transfers, meaning it can resume interrupted transfers and avoid duplicating emails.
Key characteristics:
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Transfers emails from one IMAP server to another
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Preserves folder structure and subfolders
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Keeps message flags (read, unread, flagged, etc.)
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Avoids duplicates by detecting already copied messages
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Works on Windows, Linux, and macOS via command line
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Provides a web interface for easier usage
Imapsync Online Tool (/X)
The /X interface is a graphical web version of the tool that allows users to run email migrations without installing any software.
Main features
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Copy a full mailbox between IMAP servers
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Incremental synchronization (can resume if interrupted)
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Folder hierarchy preserved
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Duplicate detection
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Log and progress output in real time
The free online service allows synchronization of mailboxes below 3 GB, while paid plans remove size and sync limitations.
When to Use the Online Tool
Use the Imapsync online interface when:
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Migrating email accounts to a new hosting provider
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Moving mailboxes between servers
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Backing up an IMAP mailbox
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Copying email from one account to another
Examples:
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cPanel → Gmail
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Gmail → Microsoft 365
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Old hosting → new server
Required Information
Before starting the migration, you need the following details for both mailboxes:
Source Mailbox
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Email login (usually full email address)
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Password
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IMAP server hostname or IP address
Destination Mailbox
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Email login
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Password
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IMAP server hostname or IP address
How to Use the Imapsync Online Tool
Step 1 — Open the Web Interface
Go to:
https://imapsync.lamiral.info/X/
Step 2 — Enter Source Mailbox Details
Fill in:
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IMAP source login
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Source password
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Source IMAP server
Step 3 — Enter Destination Mailbox Details
Fill in:
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IMAP destination login
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Destination password
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Destination IMAP server
Step 4 — Optional Checks
The interface also allows diagnostic tests:
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Check credentials
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Show folder sizes
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Create folders only
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Verbose mode (test run)
Step 5 — Start Synchronization
Click:
Go sync!
The migration will begin and the page will show:
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Progress bar
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Console output
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Log details
Do not close the browser tab while synchronization is running.
Important Notes
1. Browser Session Timeout
The web interface may stop if the session times out. The current timeout limit is approximately 1 hour.
2. Password Compatibility
Special characters in passwords may cause login failures in some IMAP servers. In such cases, try using a temporary password with standard characters.
3. Destination Mailbox Changes
Imapsync only reads data from the source mailbox but writes data to the destination mailbox (creates folders and copies messages). Testing on non-production accounts is recommended.
4. Contacts and Calendars
Imapsync migrates emails only. Contacts and calendars must be migrated separately using other tools.
Limitations
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Free version supports mailboxes under 3 GB
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Browser must stay open during synchronization
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Contacts and calendars are not migrated
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Not suitable for continuous two-way synchronization
Best Practices
For successful migrations:
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Temporarily disable security restrictions like IP blocking
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Use test accounts before migrating production mailboxes
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Run the sync multiple times to ensure all messages are copied
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Keep the source account active until migration completes
Alternative Methods
Instead of the online tool, you can use:
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CLI Imapsync (for large migrations or automation)
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Email clients (e.g., Thunderbird drag-and-drop)
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Dedicated migration tools provided by hosting companies
✔ Summary:
The Imapsync online interface provides a simple way to migrate IMAP mailboxes without installing software. It securely copies emails from a source mailbox to a destination mailbox while preserving folder structure and avoiding duplicate messages.
