Manual method
- On your Mac, enable your own iCloud Mail account in Apple Mail and let folders finish synchronizing.
- Check that old messages and their attachments open while offline.
- Select the mailboxes to preserve and choose Mailbox, Export Mailbox.
- Save each .mbox package to a dated folder, then import a test copy through File, Import Mailboxes to verify it.
What you get: The route uses Apple Mail’s mailbox export, not an iCloud website bulk-download button. Check every folder you need. A local cache with missing attachments is not a complete independent archive; leave the account connected until content is available. Provider instructions.
Size and waiting time
Planning example: 3 GB; light/heavy scenarios: 0.1–30 GB. These are estimates, not a measured population average or fixed limits. About 15,000 messages averaging 200 KB with attachments; personal mail activity and retention drive the total.
Preparation: No provider archive queue. Allow minutes to hours for synchronization and export, depending on mailbox size.
Network transfer of 3 GB: about 57 min at 10 Mbps, 11 min at 50 Mbps, or 6 min at 100 Mbps. This assumes 70% sustained throughput and excludes preparation, manual work and extraction. For local exports, this is a comparison for transferring the saved files online; disk speed determines local copy time. Online backups use your upload speed. Transfer calculations and large-file examples.
Store and check your archive
An encrypted external SSD or hard drive is a good main archive for this collection. Allow roughly 9 GB of working space for the example, including an original, an extracted working copy and room to check it. Very compressed packages can need more. A USB key is useful for a spare copy, but should not be the only one. An encrypted online copy protects against losing the local devices.
Keep the original in icloud_mail/YYYY-MM-DD/original/. Record the account alias, selected scope, date range and missing items. Open old and recent records and sample attachments offline, then compare file sizes or checksums after copying. Keep the source account until you have checked the result. Storage and recovery instructions.
Sources and review
Public documentation was reviewed on 27 October 2026. No signed-in export or restoration was performed. Account options and availability can change; follow the current provider instructions.