IMAP to IMAP Migration Tool
IMAP to IMAP migration transfers email data from one IMAP-enabled mail server or provider to another. It is commonly used when changing hosting providers, consolidating mail systems, moving between cloud and self-hosted environments, or relocating mailboxes while keeping users on an IMAP-based email platform. Standard IMAP migration is primarily email-focused and can transfer supported messages, attachments, folders, folder hierarchy, and common message properties exposed by the source and accepted by the target.
The EdbMails IMAP Migration Tool provides a guided IMAP to IMAP migration workflow for single users and bulk mailbox projects. It supports standards-compliant IMAP environments and widely used providers such as Gmail, Outlook.com, Yahoo Mail, Zoho Mail, Zimbra, cPanel, Plesk, GoDaddy, Rackspace, Amazon WorkMail, and other IMAP-enabled systems. Administrators can connect source and target accounts, load users through CSV, select mailboxes and folders, review source-to-target mapping, apply filters, start the migration, and verify the result from migration reports.
For larger projects, EdbMails supports concurrent mailbox processing, with 10 mailboxes processed in parallel by default and a configurable maximum of 20, subject to source and target connection limits, bandwidth, and migration-computer resources. Incremental migration can process eligible new or changed email items in follow-up passes, which is useful for staged cutovers. Users can generally continue working in the source mailbox during the copy phase, but DNS, MX, account, and client changes required for the final cutover should still be planned and validated.
IMAP migration scope: IMAP does not normally migrate contacts, calendars, tasks, rules, or other non-mail workloads. If these are required, plan a separate provider-specific or application-specific migration method.
Why use EdbMails for IMAP to IMAP migration?
- Bulk mailbox migration: Prepare multiple source and target accounts through CSV instead of configuring every mailbox individually.
- Concurrent processing: Process multiple mailboxes in parallel, with 10 concurrent mailboxes by default and a configurable maximum of 20.
- Incremental migration: Run follow-up passes for eligible new or changed email items to support staged migration and cutover.
- Mailbox and folder mapping: Review automatic mappings and adjust source-to-target relationships where account names or folder structures differ.
- Selective migration: Apply supported filters and folder exclusions to reduce unnecessary transfer volume.
- Migration reports: Review mailbox and folder status, migrated item counts, errors, and warnings before completing the migration project.
See the IMAP to IMAP migration video for a visual walkthrough.
IMAP to IMAP Migration Plan
Before moving production mailboxes between IMAP servers, define the source, target, mailbox scope, authentication method, migration schedule, and cutover plan.
- Inventory source mailboxes, mailbox sizes, active accounts, IMAP host names, ports, TLS requirements, and authentication methods.
- Confirm the migration scope. Standard IMAP covers email, folders, attachments, and supported message properties; contacts, calendars, tasks, and rules require a separate workflow.
- Prepare the target accounts and confirm that IMAP access is enabled and the required storage quotas are available.
- Identify provider-specific connection limits, message-size limits, throttling, and authentication requirements on both the source and target.
- Decide whether the project will use a single migration pass or a staged approach with follow-up incremental passes.
- Review the source-to-target mailbox mapping, including renamed users, consolidated accounts, and custom folder mappings.
- Estimate network and migration-computer capacity before increasing mailbox concurrency.
- Run a pilot migration with representative mailboxes and verify folder structure, attachments, message properties, and the migration report.
- Communicate any final MX, DNS, account, password, or client-configuration changes required for the provider cutover.
- After the final pass, verify mail flow and target mailbox data before decommissioning the old environment.
IMAP to IMAP Migration Prerequisites
- Source IMAP details: Confirm the source host name, port, TLS/SSL requirement, email address, and authentication method. IMAP access must be enabled for the source account.
- Target IMAP details: Confirm the destination host name, port, TLS/SSL requirement, target account, available mailbox quota, and authentication method. IMAP access must also be enabled on the target.
- Bulk mailbox list: For multiple users, download the EdbMails sample CSV and enter the required source or target mailbox details. Validate a small test set before loading the full production list.
- Provider-specific authentication: Use the authentication method supported by each provider. For Gmail or Google Workspace, use an app password only where the account policy and selected EdbMails workflow permit it.
- Connection and throttling limits: Check whether either provider limits simultaneous IMAP sessions, per-user connections, per-IP connections, or message sizes. These limits affect useful migration concurrency.
- Pilot migration: Test representative mailboxes before starting a large batch and confirm the expected folder mapping and item behavior.
Step-by-Step Guide for IMAP to IMAP Migration
Step 1: Download and install EdbMails IMAP migration tool
- Download and install EdbMails on your computer.
See EdbMails system requirements for IMAP to IMAP migration
- Start the EdbMails application on your computer.
- Enter your registered email address and password, then click ‘Login’. If you do not have an account, click ‘Start Your Free Trial’ to use the trial version.Note: The free trial lets you evaluate the IMAP migration workflow and migrate up to 30 items from each folder. To migrate all eligible items for licensed mailboxes, purchase the required IMAP migration license.
- Select the ‘IMAP (Gmail, Outlook & more) Migration’
- Select ‘IMAP to IMAP Migration’.
- You may move forward with the preassigned default job name, or click on ‘New Job’ to change the name as per your preference before proceeding further.
- Download and install EdbMails on your computer.
Step 2: Connect to the Source IMAP Server
- To migrate a single account, select ‘Single User / Account Migration’, choose the required option such as ‘Connect to IMAP Server’ or ‘Connect to POP3 Server’, and click ‘Next’ to proceed to the next step.
- Choose the correct source IMAP host name from the list or enter it manually, then provide the source email address and the authentication credential required by that provider. For Gmail or Google Workspace, use an app password only where the Google account policy and EdbMails workflow allow it.
- Click the ‘Login’ button.
- For migrating multiple mailboxes, choose ‘Multiple (bulk) Users/Accounts Migration’, then select the appropriate option such as ‘Connect to IMAP Server’ or ‘Connect to POP3 Server’, and then click ‘Next’.
- Click ‘IMAP Migration CSV File’ for downloading the ‘Sample.CSV’ file.
- Edit the source CSV with the required email address, authentication credential, IMAP host name, and port for each mailbox, then save the file.
- Close the CSV file, then click the ‘Load Modified CSV File’ button and choose the updated CSV file to proceed.
- Verify the mailboxes, and click 'Next'.
- To migrate a single account, select ‘Single User / Account Migration’, choose the required option such as ‘Connect to IMAP Server’ or ‘Connect to POP3 Server’, and click ‘Next’ to proceed to the next step.
Step 3: Select the Source IMAP Server Mailboxes
- Select the mailboxes or particular folders you want to migrate and once your selection is complete, click ‘Next’ to continue.
- Select the mailboxes or particular folders you want to migrate and once your selection is complete, click ‘Next’ to continue.
- Step 4: Connect to the Target IMAP Server
- To connect an individual target account, select ‘Single User / Account Migration’, choose ‘Connect to IMAP Server’, and click ‘Next’.
- For a single-user target login, choose the correct IMAP host name from the list or enter it manually, then provide the target email address and the authentication credential required by that provider. For Gmail or Google Workspace targets, use an app password only where the account policy and EdbMails workflow allow it.
- Click the ‘Login’ button.
- For enabling the migration of multiple IMAP accounts simultaneously, select ‘Multiple (bulk) Users/Accounts Migration’ and click ‘Next’.
- Click ‘IMAP Migration CSV File’ to download the ‘Sample.CSV’ file.
- Update the target CSV with the required email address, authentication credential, IMAP host name, and port for each destination mailbox, then save the file.
- Close the CSV file, click the 'Load Modified CSV File' button, select the modified CSV file.
- Verify the mailboxes, and click 'Next'.
Refer to the EdbMails detailed steps on connecting to single and multiple users during IMAP migration.
- To connect an individual target account, select ‘Single User / Account Migration’, choose ‘Connect to IMAP Server’, and click ‘Next’.
- Step 5: Map source and target mailboxes
- Choose the required mailbox mapping option.
- EdbMails can automatically map source and target IMAP mailboxes using the available mailbox identifiers. Review the mapping before starting a bulk migration.
- You can also map source and target mailboxes manually when automatic matching is not appropriate, such as renamed users, consolidated accounts, or different target naming conventions.
- Choose the required mailbox mapping option.
- Step 6: Start IMAP to IMAP migration
- Verify both the source and target mailboxes before completing the mapping process.
- Click the ‘Settings’ button to apply the filters. For example, you can set a date filter to migrate only the data within a certain date range.
- Click the ‘Start Migration’ button and initiate the migration process.
- Click the ‘View Log’ button to review the migration report. Check mailbox and folder status, migrated item counts, errors, and warnings. Investigate failed or skipped items and run the required retry or incremental pass before completing the migration.
- Also, log in to your target server and verify the migrated items.
IMAP to IMAP Post-Migration Tasks
- Verify the final migration pass
Review the migration report and verify representative folders, messages, attachments, and item counts on the target. Resolve failures and run any required retry or incremental pass before cutover.
- Validate mail flow on the target
Send and receive test messages and confirm that the target mailbox is working as expected from the clients and devices that users will use after the migration.
- Update DNS or MX records only when the provider cutover requires it
If the organization is changing the mail-routing destination for its domain, update the required MX and related DNS records after the target has been validated. If the migration does not involve a domain mail-flow change, an MX change may not be necessary.
- Monitor the source during the transition
Keep the source available for the agreed validation period where practical, and confirm that no required new mail remains only on the source before decommissioning it.
- Verify the final migration pass
Troubleshooting IMAP to IMAP Migration
For authentication, connectivity, mapping, filtering, throttling, or item-level issues, review the IMAP migration knowledge base and the IMAP migration FAQ. Use the migration report to identify the specific mailbox or item that requires attention before rerunning the job.
If additional help is required, contact EdbMails support.
Why choose EdbMails IMAP to IMAP Migration Tool?
- Concurrent mailbox migration
EdbMails can process multiple IMAP mailboxes in parallel rather than migrating every account sequentially. The default mailbox-level concurrency is 10 and can be configured up to 20, subject to network capacity, source and target limits, and migration-computer resources.
- Incremental migration for staged cutovers
After the initial pass, EdbMails can process eligible new or changed email items in follow-up runs. This reduces repeated processing and supports staged migration projects where users continue working in the source until final cutover.
- Selective email and folder migration
Use supported filters and folder exclusions to limit the migration to the required email data. Review the IMAP migration filter settings before starting the production job.
- Automatic and manual mailbox mapping
EdbMails can map source and target mailboxes automatically and also allows manual correction when user names, mailbox addresses, or destination structures differ. Always review mappings before starting a bulk project.
- Preserves supported email properties
EdbMails is designed to preserve supported email messages, attachments, folder hierarchy, and common message properties exposed by the source and accepted by the target. Provider-specific limits can affect individual items, so use migration reports and target-side checks as part of verification.
- Works with IMAP-enabled providers and servers
The tool supports standards-compliant IMAP environments and widely used providers such as Gmail, Outlook.com, Yahoo Mail, Zoho Mail, Zimbra, cPanel, Plesk, GoDaddy, Rackspace, Amazon WorkMail, and other IMAP-enabled systems. Connection success depends on IMAP availability, authentication requirements, and network access.
- Runs on supported Windows environments
For production migrations, use a currently supported Windows client or Windows Server release and verify the current CPU, memory, storage, and network requirements on the IMAP supported platforms page.
- Free trial and 24/7 technical support
Use the free trial to test representative mailboxes before purchase. EdbMails also provides 24/7 technical support for migration planning, connection issues, mapping, errors, and verification.
IMAP to IMAP Migration FAQs
- What is IMAP to IMAP migration?
IMAP to IMAP migration copies supported email data from one IMAP-enabled mailbox or server to another. It is commonly used when changing email providers, consolidating systems, or moving between cloud and self-hosted IMAP environments.
- What data can be moved in an IMAP to IMAP migration?
Standard IMAP migration is primarily for email messages, attachments, mailbox folders, folder hierarchy, and common message properties. Contacts, calendars, tasks, and rules normally require a separate migration method.
- Can EdbMails migrate multiple IMAP mailboxes at once?
Yes. Multiple accounts can be loaded through CSV and processed in parallel. EdbMails uses 10 concurrent mailboxes by default and supports a configurable maximum of 20, subject to the source, target, network, and migration-computer limits.
- Does EdbMails support incremental IMAP to IMAP migration?
Yes. After the initial pass, follow-up runs can process eligible new or changed email items, which is useful for staged migrations before the final cutover.
- Do I always need to change MX records after IMAP to IMAP migration?
No. MX or DNS changes are required only when the mail-routing destination for the domain changes. If the project is only copying mailbox data without changing domain mail flow, an MX change may not be necessary.
- How should I verify an IMAP to IMAP migration?
Review migration reports, check representative folders and item counts on the target, verify attachments and important message properties, test mail flow, and resolve errors before retiring the source environment.
