Email

How do I migrate email from another provider without losing mail?

We use IMAP-to-IMAP sync — your existing mail copies in the background, then you cut over MX records. Zero mail loss if done in this order.

The safe order

The trick to a zero-loss email migration is to copy mail before flipping MX records, so nothing arrives at the new server that is not also on the old one.

  1. Provision your mailboxes at PhotonSpark. Each mailbox gets the same username and password as the source (or we map them).
  2. Run an IMAP sync. We pull every folder and every message from your old provider into the new mailbox. Typically 1–6 hours depending on volume. You and your team keep using the old provider during this.
  3. Pause the sync, run a delta sync. Quickly catch any messages that arrived during step 2.
  4. Lower the old MX TTL to 300 seconds. Wait one TTL.
  5. Update the MX records to point at our servers. Mail starts flowing here.
  6. Run a final delta sync to catch the few messages that arrived during DNS propagation.

Total wall-clock time: 1–2 days for small accounts, 3–7 days for larger ones (>50 mailboxes).

Source providers we have ready-made syncs for

  • Microsoft 365 / Exchange Online
  • Google Workspace
  • Zoho Mail
  • Generic IMAP (cPanel, Plesk, mail-in-a-box, anything else)
  • IMAPS-only providers (we handle the TLS).

What does not transfer automatically

  • Sent-Items archive — yes, this transfers, but if your client is "leaving sent on server: no" you may have local-only mail. Tell your users to enable server-side sent items 1–2 weeks before the migration.
  • Calendar and Contacts — handled via separate CalDAV/CardDAV sync if you use them. Mention these at the start.
  • Old aliases / forwarders / catchalls — we recreate these manually from a list you provide.

Cutover plan template

For team accounts, we send a 1-page cutover plan with the exact times and contact for the cutover engineer. Standard accounts can self-serve via the migration wizard in the portal.