Don't Drop The Attachment! Using Microsoft Exchange 2007 to produce in a "Native" Format


Nothing sharpens your focus like a $206,000 question! 


In the case of PSEG Power of New York v. Alberici Constructors, Inc. the court wrestled with the e-discovery issue of whether or not PSEG had to produce 3,000 emails and their corresponding attachments together.


It seems that PSEG's original production contained emails separated from their attachments, or the links to the attachments were broken. PSEG argued that re-attaching the attachments would cost $206,000; Alberici Constructors said it was more like $37,500.


The Court called the email attachment issue a "fiasco" and ordered PSEG to produce the emails with attachments at its own expense. We never do get to find out how much it cost to comply with the order, but it's an entertaining read nonetheless: this one issue took six months to resolve. Electronic Discovery Blog posts the whole thing here:


As usual, I  have no idea which email system was actually in use, so let's explore the hypothetical case of Contoso Corporation running Microsoft Exchange 2007. Contoso has been instructed to produce emails with attachments in "native" format.


The "native" format for Exchange is actually somewhat debatable. In PSEG Power of New York v. Alberici Constructors, Inc., the Court cited FRCP Rule 34(b), which mentions two alternative forms of production in the event the parties do not reach agreement on the file format during their meet-and-confer: the form “in which it is ordinarily maintained” or “in a form or forms that are reasonably usable.”


Another interesting read, and one that specifically mentions Exchange file formats, is Craig Ball's post on "Quasi-Native format."  In the article, he wrestles with various email and database formats like .eml, .edb, .pst,  and their pros and cons. You can find it here:


If you're super-motivated,  the Sedona Principles Addressing Electronic Document Production, Second Edition (June 2007),  explore the issues around Rule 34(b), "native form," "reasonably usable," and forms of production in depth. The full document is available here:


Let's assume that Contoso's legal team has decided to produce the emails and attachments in a separate .PST file that contains only the responsive messages. All of the email metadata (such as headers, message ID, conversation ID)will be intact, the attachments will be attached and in native format (like Word, Excel), and the .pst file won't contain other messages.


How can Exchange 2007 export do that?


Once again, the best Exchange commands are PowerShell one-liners. This time, we're going to use the Export-Mailbox cmdlet. Export-Mailbox has a parameter called "-AttachmentFilenames" that lets you extract email messages with certain attachment types, as well as a "-PSTFolderPath" parameter that lets you specify a PST file as the export target.


You can see the documentation on Export-Mailbox here:


Here is how we would copy all the messages out of John's mailbox that contained the keyword "merger" and attachments with filenames matching "orgchart"


Export-Mailbox -Identity contoso\john -TargetMailbox ExportMailbox -TargetFolder MyData -ContentKeywords "merger" -AttachmentFilenames "*orgchart*"


The Microsoft Exchange team blog explores the Export-Mailbox cmdlet in further detail, with plenty of additional examples, including how to export from multiple users' mailboxes at the same time, how to specify a .PST target, and some other interesting uses of the cmdlet. You can see  it here: .