imapsync vs Stellar Migrator for Exchange

imapsync is an IMAP transfer tool for migrating or backing up mailbox accounts. Its command-line software makes incremental, recursive transfers, and a stopped transfer can be restarted without generating duplicates. The software runs on Windows, Mac OS X and Linux, with listed compatibility including Gmail, Office 365, Exchange, Dovecot and Zimbra. The online service offers free mailbox syncs below 3 GB; buying provides unlimited syncs of any size. Buyers also receive a visual interface for installation on a Linux server, though that interface does not yet work on Windows. Staged and tenant-to-tenant moves are supported, including for Microsoft 365 and Google Workspace. The software-only plan is €72 as a one-time purchase; professional support is €144, paid once, as is the Imapsync + support plan. There is no trial version, and purchases carry a 30-day money-back guarantee. The tool cannot migrate contacts or calendars, maintain two-way synchronization between active accounts, or transfer messages to or from a local directory.

Stellar Migrator for Exchange moves mailboxes among Exchange Server and Microsoft 365 environments, including transfers between Microsoft 365 tenants. It supports primary, shared, and archive mailboxes as well as public folders, and can run cutover, staged, or hybrid migrations all at once or in batches. Delta migration transfers new or changed data after an initial move. Up to 10 mailboxes and their items can be migrated simultaneously. Users can match mailboxes automatically or map them manually, including with a CSV file, select folders such as email, contacts, calendars, tasks, notes, and journals, and filter mail by date range. Failed or incomplete migrations can be rerun, with automatic retries set from 1 to 5 attempts. It runs on Windows and requires at least 8 GB of memory. The free trial covers 2 mailboxes and includes all migration capabilities; Mailbox Pricing is $250, paid once, billed $10 Per Mailbox, with quantity selected on the page and one license per source mailbox.