Cloudiway Mailbox Migration Tool vs imap-migrate

Cloudiway Mailbox Migration Tool is a web service for moving mailbox data from supported systems into Microsoft 365 or Google Workspace. Sources include Google Workspace, Microsoft Exchange on-premises and Online, Zimbra, Lotus Notes/Domino, and IMAP servers. It transfers emails, contacts, calendars, tasks, notes, inbox rules, shared mailboxes, distribution lists, and archives. Delta sync keeps users working during migration and captures changes made before cutover. Automated provisioning, folder mapping, error handling, and date-range, folder, and content filters provide migration controls. A real-time dashboard shows progress, statistics, and issues, while parallel processing can handle thousands of mailboxes simultaneously. The service supports OAuth 2.0 on supported platforms, TLS 1.3 in transit, and AES-256 at rest. Cloudiway lists ISO 27001:2022, GDPR compliance, Microsoft SSPA certification, and HIPAA readiness. Migration data is automatically purged afterward, with European and EU-only processing options available on request. Plans start at $570, paid once, and a free trial uses real data without requiring a credit card.

imap-migrate is a free, open-source command-line tool for transferring the contents of one email folder between IMAP hosts. It can work with providers that support IMAP, including Gmail, Outlook, Fastmail, Yahoo and custom servers. The tool preserves original received dates and flags such as Seen and Flagged, and shows progress, transfer speed, success and error counts, plus estimated time remaining. It records actions in migration.log. Its README says interrupted migrations can be rerun without duplicating emails; the --dry-run option checks connection and settings without moving messages. Credentials can be supplied as command-line arguments or environment variables, with environment variables recommended by the README as the more secure option. Both accounts need IMAP access enabled, and the tool requires Python 3.12 or higher; uv is recommended for dependency management. It runs on Linux, macOS and Windows and is licensed under MIT. It does not rebuild a full folder structure or migrate provider-specific features such as Gmail labels or categories. Bug reports and contributions are invited through GitHub issues and pull requests.