Fix CloudM Migration Dates in Outlook

CloudM Migrate handles mailbox transfers by downloading messages from the source system and uploading them to the destination. When the destination is a Microsoft Exchange or Microsoft 365 environment accessed through Outlook, each uploaded message receives a new Received header from the destination mail server. This Received header contains the timestamp of the migration, not the original delivery date.

Outlook desktop determines the date displayed in the inbox by reading the most recent Received header in each email's header chain. Since the CloudM migration header is the newest, Outlook shows the migration date for every single message. The original Date header still exists within the email, but Outlook prioritizes the Received header for its "Received" column display.

This is especially problematic for users who rely heavily on Outlook's date-based sorting and search. After a CloudM migration, the inbox becomes an undifferentiated mass of messages all stamped with the same date. Finding a specific email from a specific time period requires opening each message individually and checking the original Date header manually, which is completely impractical for mailboxes with thousands of messages.

Outlook's "Received" column shows the migration timestamp for every email. Date-based sorting becomes useless because all messages are grouped under a single date. The "Arrange by Date" view, which is Outlook's default, presents the entire mailbox as one flat block instead of the familiar chronological groupings (Today, Yesterday, Last Week, Last Month, Older).

Outlook's Quick Search and Advanced Find features are impacted when filtering by date. Users who search for "emails received last month" or "emails from January" get no results (or all results, depending on when the migration occurred) because Outlook searches against the corrupted Received date. Outlook rules that process emails based on when they were received also malfunction. Auto-archive settings that move emails older than a certain date fail because Outlook sees every email as having the same recent received date.