Export of 47 GB Mailbox to PST File from Exchange 2003 Using Outlook 2010 coming up short

laserphaser used Ask the Experts™
Trying to backup my 47 GB Mailbox from SBS / Exchange 2003.  I'm using Outlook 2010's export PST file function on a Windows 7 client.   Cached Exchange Mode is turned off.  Exported PST file only contains about 5 GB of mail with mostly more recent emails.  After making backup goal is to archive old emails to get mailbox back down to a manageable size to improve performance.  Mailbox contains about 50,000 emails spanning 10 years including numerous attachments of mostly PDF's and CAD Files.  Export completes without any error messages but only exports recent emails.  Exchange / SBS is a VM utilizing a VMware ESXi hypervisor.
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Adam BrownSenior Systems Admin
Top Expert 2010

Use EXMERGE to export the mailbox. You'll have to export it in bunches, since exports from Exchange 2003 are size limited. https://demazter.wordpress.com/2010/03/23/export-mailboxes-using-exmerge-and-exchange-2003/ explains. You'll need to export on a date limited basis for each bunch.
This is why Exchange admins have pleaded that Exchange is NOT a filing cabinet.  Files should be stored in folders on the server, not in Exchange.  For all kinds of reasons, including ease of management, ability to locate, and, last but not least, what you see here.


I'm familiar with Exmerge but it has a 2 GB limit per PST file.  Outlook 2010 is supposed to have a 50 Gb limit for exporting PST files.  Would prefer to not to have to have export 25 PST files from this mailbox to solve my problem.
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Distinguished Expert 2018
You can configure outlook 2010 / 2013 client in cached mode and let exchange download all mails as OST (47 GB) and then archive / move them in PST


I'll give that a try.
Clark KentSoftware Engineer cum Blogger
Top Expert 2014

As per my knowledge and expert’s advice, manual methods to export exchange mailbox to pst have size limitations and they will consume a lot of time and effort too. So, I will suggest you to use a third party tool which will help you to migrate large amount of data in countable minutes.
Thanks and Regards
Clark Kent
E ATech Lead

You can safely and easily migrate Exchange Server EDB to Outlook PST.

Using PowerShell Cmdlets

For Microsoft Exchange 2010 to PST: Use ExportMailboxRequests

Using Exchange Admin Center (EAC) or Exchange Management Console (EMC)

Using Exmerge Application

Get help from below links:



Hope this helps!
AmitIT Architect
Distinguished Expert 2017

Export into multiple small pst, less then 2 GB, on a system with higher HDD RPM. Don't keep on USB drive.


Turning on Cached Exchange Mode and allowing it to sync to the ost file on the desktop did the trick.  I was able to export the entire mail folder with out any issues.

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