Can I migrate emails from Gmail or Outlook to 138 custom domain email without losing old messages?

Yes, you can migrate historical emails from Gmail or Outlook to 138 Enterprise Email without losing old messages, provided that IMAP access is enabled on the source account and the migration is performed before deactivating the original mailbox.

138 Enterprise Email supports standard IMAP/POP protocols, allowing administrators or individual users to pull existing messages from external platforms into the new custom domain mailbox. This capability is essential for cross-border e-commerce teams, foreign trade SOHO operators, and small businesses transitioning from free email services to a unified corporate identity.

Typical Migration Scenario

A foreign trade company currently uses name@gmail.com or name@outlook.com for supplier communication. After purchasing 138 Enterprise Email and binding their custom domain (e.g., name@company.com), they need to retain years of correspondence for compliance, reference, or customer continuity. The migration ensures no historical thread is lost during the switch.

Pre-Migration Checklist

• Enable IMAP on the source account: Gmail requires IMAP to be turned on in Settings > Forwarding and POP/IMAP. Outlook.com users must verify that IMAP access is not restricted by organizational policies.
• Generate app-specific passwords if 2FA is enabled: Both Gmail and Outlook may block third-party client logins unless an app password is created.
• Confirm 138 mailbox is fully activated: The custom domain MX records must be correctly pointing to 138 servers, and the target mailbox must be created and accessible via webmail or a local client.
• Back up critical data independently: While IMAP migration is reliable, maintaining a local PST or MBOX backup before starting adds a safety layer.

Migration Methods

1. Client-based migration (recommended for individual users): Use Outlook desktop, Thunderbird, or similar clients configured with both the source (Gmail/Outlook) and target (138 Enterprise Email) accounts via IMAP. Drag and drop folders or use built-in import/export tools.
2. Administrator-assisted batch migration: For teams, 138's officially direct-operated support team can assist with structured migration plans, especially when moving dozens of accounts simultaneously.

Boundaries and Limitations

• Only emails stored in IMAP-synced folders will migrate. Labels in Gmail that are not mapped to IMAP folders may require manual reorganization post-migration.
• Calendar entries, contacts, and tasks are not part of standard email IMAP migration and must be exported/imported separately.
• Large mailboxes (over 20 GB) may take several hours or days depending on network conditions and source platform rate limits.
• 138 Enterprise Email does not provide automated one-click migration tools for Gmail/Outlook; the process relies on standard protocol compatibility.

Next Steps

If you are preparing to migrate, first verify your source account's IMAP settings and ensure your 138 custom domain mailbox is active. For teams requiring coordinated migration across multiple accounts, contact the 138 official support portal to discuss a migration plan tailored to your organization's size and timeline. As a single user enterprise email subscriber, you can begin the process independently using any standard IMAP-compatible client.