An Outlook Data File (.pst) contains your messages and other Outlook items and is saved on your computer. That is, it is a personal folder file in Microsoft Outlook. Outlook data file used to store local copies of messages, calendar events, and other items from your Exchange mailbox.

When importing or exporting a pst file and prompted with the following error as described, kindly follow these steps.
– This can be achieved by reducing it with different values, i.e… if the mailbox exceeds the maximum number of large items that were specified for this request.

This happens as a result users having emails in the PST file that are larger than the Send/Receive limits in exchange.An example is when users have both send and receive limit set to over 10mb.

Solution: There is also a parameter for New-MailboxImportRequest which is -Largeitemlimit.
Note: The LargeItemLimit parameter specifies the number of large items to skip if the request encounters such items in the mailbox.
– Use 0 to not skip any large items.
– If any number above 50 is specified, the AcceptLargeDataLoss parameter must also be specified.

The default value is 0. We recommend that you use the default value of 0 and increase the LargeItemLimit only when large items are encountered. so if you were to use -largeitemlimit 20 for example, it would allow the mailbox to be imported but it would not import those larger items.
– Try changing the send/receive values to something high and see how it goes.
– Also, you could open some of the PST files and sort by size to see what sort of email item sizes you are dealing with.

I hope you found this blog post helpful. If you have any questions, please let me know in the comment session.