Fix BitTitan Migration Dates in Microsoft 365

BitTitan MigrationWiz uses EWS or IMAP to upload messages into a Microsoft 365 tenant during migration. Microsoft 365 keeps the date each copy is given: when MigrationWiz passes the original date, the copy keeps it; when it doesn't, the copy gets the moment of the upload - the migration timestamp, not the original date. That date becomes the reference for the entire M365 ecosystem.

Microsoft 365 stores this as the message's INTERNALDATE (the PR_MESSAGE_DELIVERY_TIME property in Exchange terms). Every client connected to the M365 mailbox reads it. Outlook desktop. Outlook on the web. Outlook mobile. Third-party IMAP clients. All of them show the migration date. A mailbox with eight years of email history suddenly looks like everything arrived on a Tuesday in March.

Look - this is not a rare edge case. It can happen on any BitTitan migration into M365, regardless of the source platform. On-premises Exchange, Google Workspace, Zimbra, GroupWise. The destination behavior is always the same: Microsoft 365 keeps the date it's given, so when that date is the upload date, that date wins.

The result? IT teams get buried in tickets the morning after migration. Users cannot find emails by date. Executives who relied on chronological email history for reference lose months or years of context overnight.

Every M365 application reads the corrupted date. Outlook on the web, Outlook desktop, Outlook for Mac, Outlook mobile - they all display the wrong received date. Microsoft Copilot and AI features that reference email timelines produce incorrect results because they rely on the same corrupted metadata.

Compliance is where it really hurts. Litigation holds, retention policies, and eDiscovery searches in the Security and Compliance Center all filter by date. When every email carries the migration timestamp, date-based queries are useless. An administrator asked to produce all emails from Q3 2023 for a legal matter gets back either nothing or the entire mailbox. That is not a minor inconvenience - it is a compliance failure.

Redate.io addresses this through safe low-level message handling with per-message verification. Each email is processed individually, and the original date is restored at the server level so the correction propagates to every connected client and compliance tool automatically. No re-migration, no manual intervention, no data loss.