imap-migrate vs Inbox Hop

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.

Inbox Hop migrates email, calendars, and contacts among Microsoft 365, Google Workspace, and on-premises Exchange. Projects can move data cloud-to-cloud, from cloud to on-premises, or in the reverse direction. Microsoft 365 connections use Exchange Web Services with guided Azure app registration and permission checks. Google Workspace uses Google APIs and service-account domain-wide delegation, avoiding per-mailbox credentials. After scanning, the platform suggests mailbox matches; users can change assignments or create missing destination mailboxes automatically. Run modes include scanning, folder-structure-only copies, full migrations, and incremental delta runs. A full migration consumes one prepaid credit per mailbox regardless of data volume, while scans and delta runs use no credits. On-premises Exchange can connect directly over HTTPS or through a Windows connector that polls outbound HTTPS without inbound firewall rules. Monitoring shows transfer rate, items per minute, health, and chronological logs. Inbox Hop describes encrypted connection secrets, tenant isolation, role separation, permission validation, and append-only audit records. It is intended for organizations changing mail platforms.