Fix Manual IMAP Copy Dates in Outlook

Here is what actually happens when you drag emails between two IMAP accounts in Outlook. Outlook downloads the message from the source server, then uploads it to the destination using an the standard mail transfer protocol command. During that upload, the destination server stamps a brand-new Received header with the current date and time. The INTERNALDATE - the value Outlook uses for its "Received" column - gets set to the moment of upload, not the moment the email was originally delivered.

The critical detail most people miss: Outlook has zero mechanism for telling the destination server "this message originally arrived on June 3, 2019." The APPEND command Outlook issues does not include a date parameter. Compare that to dedicated migration tools, which at least attempt to pass the original date (even if they sometimes fail). Outlook does not even try.

Think about it. You select 4,000 messages in your old inbox, drag them to the new account, and 20 minutes later every single one shows today's date. The original Date header buried inside each email still holds the correct timestamp. But Outlook never looks at that header for its column display. It trusts the server's INTERNALDATE exclusively.

What makes this worse is the false confidence factor. People choose the manual drag-and-drop approach because it feels safe and controllable. No third-party tools, no scripts, no migration wizards. Just Outlook doing Outlook things. The date corruption only becomes visible after the copy finishes - sometimes after the source account has already been decommissioned.

Every copied message now displays the copy date in Outlook's "Received" column. Sorting by date? Useless - 4,000 emails from different years all clumped on one day. Outlook's date-based groupings (Today, Yesterday, Last Week, Last Month, Older) collapse into a single block. Quick search with a date range returns either everything or nothing, depending on whether you search for the real date or the copy date.

A particularly frustrating scenario: you manually copied only your Sent Items and a couple of project folders, leaving the rest intact. Now your mailbox contains a mix of correctly-dated emails (the ones that were already on the destination) and incorrectly-dated ones (the ones you dragged over). There is no visual indicator in Outlook telling you which messages have corrupted dates and which do not. Redate.io's proprietary correction engine scans the entire mailbox, identifies exactly which messages have mismatched dates, and applies targeted metadata correction without altering message content - fixing only what needs fixing and leaving everything else untouched.