A final mail synchronization reduces the gap between an initial Plesk migration copy and mail delivered during the cutover. Mail can continue reaching the old server while senders use cached DNS, so the transition needs observation and a supported resynchronization process rather than a single copy followed by immediate deletion.
IN THIS ARTICLE
What you need before you begin
Confirm the migration source and mail-server combination support the intended re-sync. Record mailbox inventory, aliases, forwarders, quotas and current MX records. Keep backups, preserve the migration session and identify which server users should access during the transition.
01 Complete a final mail sync during a Plesk migration
- Complete the initial migration and test destination mailbox authentication, folders and messages. Verify that the new mail service can receive externally and send through the intended authenticated route.
- Review the migration re-sync options and select mail content deliberately. Do not run a whole-subscription data sync when only mail is required without assessing file and database overwrite behaviour.
- Coordinate the DNS change and user connection settings. Retain the old server while cached MX destinations may still receive messages. Avoid configuring both systems to forward endlessly to each other.
- Run the supported final or repeated mail re-sync as required by the migration plan. Read the detailed result for individual mailbox failures and record the synchronization time.
- Compare representative folders and recent messages from both sides. Check destination quota and identify any source mailbox still receiving mail before closing the migration.
How do I confirm the final mail synchronization?
Send and receive with independent external accounts and test a mailbox that received mail near the cutover time. Confirm mobile and desktop clients connect to the intended server with valid TLS. Monitor the old server for late arrivals during the agreed transition period.
Troubleshoot unexpected results
If mail is missing, locate whether it reached the old server, new server, a forwarder or a queue before copying again. Do not delete source mailboxes or recreate destination mailboxes as a first repair. Re-sync behaviour varies by source and content type, so verify whether deletion and flag changes are included. Preserve both mailbox states until discrepancies are understood.