Exchange OnlineでのBitTitan MigrationWiz移行日付の修正
BitTitan MigrationWizの移行がExchange Onlineで間違った日付を表示する理由
Exchange Online is the mail backend powering Microsoft 365 メールボックス, and BitTitan MigrationWiz is frequently used to migrate メールボックス from on-premises Exchange, Lotus Notes, GroupWise, or other platforms into Exchange Online. During the migration, MigrationWiz uploads each message using EWS or IMAP APPEND, and Exchange Online's transport pipeline stamps each message with a Receivedヘッダー containing the upload timestamp.
Exchange Online uses this Receivedヘッダー and the associated PR_MESSAGE_DELIVERY_TIME property to determine the displayed received date. Unlike some mail systems that allow migration tools to set a custom delivery time, Exchange Online's processing consistently applies the actual upload timestamp. This means every migrated email carries the 移行日 in its delivery time metadata, に関係なく the original send date.
The problem is amplified in Exchange Online because the corrupted date propagates through all connected services: Outlook desktop reads it, OWA displays it, mobile clients show it, and Exchange Online's built-in search indexes it. PowerShell scripts that 管理者 use to query メールボックス content by date also return results based on the 移行タイムスタンプ rather than the 元の日付, complicating post-migration verification and troubleshooting.
Exchange Onlineへの影響
In Exchange Online, the corrupted delivery time affects every layer of the mail stack. The Outlook desktop client, Outlook on the web, and mobile apps all display the 移行日 in the received column. Exchange Online's search service indexes the 移行タイムスタンプ, so date-range queries in Outlook and OWA return incorrect results.
For 管理者, Exchange Online Management Shell commands like Get-MessageTrace and Search-Mailbox use the delivery time property, which now reflects the 移行日. Mailbox auditing, journaling rules, and transport rules that reference message dates all operate on the corrupted timestamps. Organizations that rely on Exchange Online's native コンプライアンス features (In-Place Hold, Retention Tags) find that these policies apply based on the 間違った日付, potentially retaining or deleting messages at incorrect intervals.
よくある質問
Is this different from the Microsoft 365 date issue?
Exchange Online is the backend service that powers Microsoft 365 メールボックス. The root cause is the same: BitTitan adds a Receivedヘッダー 移行中 that overrides the displayed date. Fixing it in Exchange Online corrects the date across all Microsoft 365 applications.
Can Exchange Online 管理者 fix this with PowerShell?
PowerShell cannot modify the Receivedヘッダーs or INTERNALDATE of existing messages in Exchange Online. The only way to fix the dates is to re-insert the corrected messages, which is exactly what Redate.io automates at scale.
Does Redate.io support Exchange Online hybrid environments?
はい。 Redate.io connects to Exchange Online メールボックス directly. Whether the 組織 runs a hybrid Exchange setup or is fully in the cloud, Redate.io can fix the 日付の破損 on any メールボックス accessible via IMAP or Exchange protocols.