CloudM Migrate vs imap-migrate

CloudM Migrate moves users, mail, files and shared data to Google Workspace or Microsoft 365. It handles mailboxes, folders, attachments, contacts and calendars, and supports more than 20 source platforms, including on-premises servers, Zimbra, Box and Dropbox. Before migration, discovery scans mailbox volumes, item counts, folder depth and potential issues. Pilot, bulk and delta passes support phased moves and data catch-up through cutover; reporting, audit logs and service logs help track progress and diagnose issues. Customers can choose CloudM-hosted deployment or run Migrate in their own infrastructure. In self-hosted deployments, migration content stays within customer-controlled infrastructure, is encrypted in transit, and temporary files use AES-256 encryption. Each license includes a 12-month migration license and unlimited catch-up runs during that period. Document version history is supported for Microsoft 365 destinations, while Google Workspace receives only the latest document version. CloudM offers serviced migration options, including planning, execution, go-live and post-migration support. Pricing is on request, with license options priced per user or data volume and serviced migration available by quote.

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.