IMAP synchronisation copies server-side folders between old and new mailboxes while preserving a controlled rollback period.
Applies to: Mailbox migrations where both old and new services support IMAP
Prepare
- Create the destination mailbox and confirm it can send and receive.
- Keep both source and destination services active during the copy and DNS transition.
- Record source and destination hostnames, port
993, usernames and folder counts. - Confirm there is enough destination and hosting-plan storage.
- Take an independent export of critical mail where possible.
Copy and cut over
- Run an initial IMAP-to-IMAP copy using a trusted migration method.
- Compare folder names, message counts and recent messages.
- Correct destination DNS/MX records at the planned cutover.
- Allow for DNS caching and keep the source accepting mail.
- Run a final incremental copy after the old service stops receiving new mail.
- Update devices with the destination secure hostname and test sending and receiving.
- Retain the source until the agreed validation and rollback period has passed.
Important: Do not delete the source mailbox merely because one device displays the copied messages. Validate the server-side folders in webmail first.
Related articles
- Hosting email settings for any email application
- Choose IMAP or POP for a hosting mailbox
- Keep a hosting mailbox synchronised across multiple devices
- Resolve a full mailbox or quota warning
- Restore email data
- Migrate hosted email
Last reviewed: 2026-07-25.
