ElephantsDataSource and destination preparation
The Google source requires live Gmail API access for each mapped user. The Microsoft destination must have an active mailbox, required licensing, IMAP application access and effective Exchange service-principal permissions before a batch can start.
Checkpointed message transfer
ElephantsData inventories messages, copies supported raw message content and records per-item outcomes. Durable checkpoints allow a retry or latest-changes pass to continue without restarting every successfully processed message.
Mailbox size and archive planning
Destination mailbox quotas and archive behavior must be confirmed before oversized mailboxes are scheduled. ElephantsData does not describe a normal custom copy as a full-fidelity native archive migration; unsupported or failed items remain visible for review.