Article ID: 2584294 - View products that this article applies to.
You use one of the following to try to migrate a user's mailbox data from your on-premises messaging environment to Microsoft Office 365:
This issue occurs if the user's mailbox contains one or more messages that exceed the 25-megabyte (MB) message limit.
FailureType : TooManyLargeItemsPermanentException
FailureSide : Target
Message : Error: This mailbox exceeded the maximum number of large items that were specified for this request. --> MapiExceptionMaxSubmissionExceeded: IExchangeFastTransferEx.TransferBuffer failed (hr=0x80004005, ec=1242)
To fix this issue, locate and remove messages that are larger than 25 MB from the user's on-premises mailbox. To do this, follow these steps:
For more info about how to import items into Outlook in Office 365, go to the following Microsoft websites:
Still need help? Go to the Office 365 Community
Article ID: 2584294 - Last Review: October 4, 2014 - Revision: 15.0
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