Exchange 2010 Message Search and eDiscovery


An important aspect of the eDiscovery process is finding all potentially responsive ESI. In other words the eDiscovery auditor must perform a search on all ESI repositories which could house responsive ESI.

Key to eDiscovery search in Exchange 2010 is to choose words, date ranges, attachment file names etc to help the auditor narrow the results set to be reviewed, but not to the point of overlooking responsive ESI. The eDiscovery keyword search in Exchange 2010 will only find exact matches of those terms input. Additionally, the eDiscovery multi-mailbox search in Exchange 2010 will not reproduce the history of the email, such as when it was opened, what folders it existed in and when, if it was deleted and when etc., something which can add a great deal of context to the ESI.

Another key in this process is the effectiveness of your system’s indexing capability. Does it index everything including metadata, the entire email message and all attachments so that when you perform a search, you find all instances of the content? And… is the index reliable?

The indexing and search functionality of Exchange 2010 is considered neither accurate nor reliable by eDiscovery industry experts. In testing by a 3rd party market research firm, it was found that:

  • Custodian display name and address searches missed more than 20% of custodian email compared to last name only searches.
  • Lists of search terms became corrupt without generating warning errors.
  • When items are placed on litigation hold, the preservation system did not preserve the critical location context or other metadata properties of content.

To the opposing counsel, these deficiencies are a prime target to call into question your eDiscovery process and maybe enough to have the Judge force you to perform the eDiscovery search again using very expensive third party services.

Although improved over the search capabilities of previous versions of Exchange, several major limitations to Exchange Search remain that should be fully understood. These limitations restrict how Exchange Search is used, and limit its ability to be a primary factor for upgrade for stand-alone eDiscovery support by most organiza­tions.

The biggest drawbacks to Exchange 2010 include:

  • Default search filters limited: Standard Microsoft Office formats can be indexed by Exchange 2010 so that eDiscovery searches can find and return these record types, but there is limited support for other common formats such as the popular PDF file format as well as audio or video file formats. By default, the content of email messages with PDF attachments are unsearchable. (see the iFilter section below)
  • No public folder search: Organizations with a significant investment in public folders will find that they cannot search across public folder data using the native Exchange Search functionality.
  • Localization and language limitations: Emails written in multiple languages are not indexed by Exchange Search. In addition, queries made in a specific language must match the locale of the local computer doing the search.
  • Encrypted messages not indexed: Messages encrypted with S/MIME encryption are not able to be indexed and are subsequently not searchable.
  • Exchange 2010 effectively has 2 indexes per mailbox: One index exists on the Exchange Server and one on the local Outlook machine. Any local PST files cannot be searched from the eDiscovery search interface. Local user search syntax and search results may differ from the network eDiscovery search.
  • Broad-brush legal holds: Legal Holds are a mailbox wide setting meaning that all content in a target mailbox is placed on legal hold. You cannot place individual objects on legal hold. Users can move, forward, reply, flag and categorize items under legal hold with no record. Metadata changes such as the email folder location are not tracked.
  • No case management: eDiscovery searches have no matter folders, audit or security for all eDiscovery group users. Searches for unrelated cases will all be thrown together with no ability to set security by matter.
  • Metadata can be changed on export: According to a report, email exported from the Exchange archive mailbox could have the Creator, Last Modified, PR_Creation_Time, Conversation Index and even message size changed

A question corporate General Counsels need to ask themselves and their IT departments is; can I respond to an email discovery request quickly enough and in a defensible manner to satisfy the opposing counsel and Judge?

To answer that question, you need to consider another question. Is Exchange 2010 indexing everything in my system so that when you conduct a search it will find all relevant content?

The answer is probably not. The question of completeness of the eDiscovery search capability in Exchange 2010 is a big issue many don’t even think to question.

Can you rely on the Exchange eDiscovery search to produce the results so that 1: all potentially responsive ESI can be found and placed on a litigation hold and 2: does the results you end up with contain all potentially responsive ESI?

The coming collision of “free to the public cloud storage” and eDiscovery


The discovery process is tough, time consuming and expensive. What new problems are corporate attorneys facing now with the availability of “free to the public cloud storage”?

First, what is “free to the public cloud storage”? For the purposes of this blog I will define it as a minimum amount of storage capacity offered by a third party, stored and accessible via the internet made available to the public at no cost (with the hope you purchase more). The cloud storage offerings I’ve already mentioned do not limit the types of files you can upload to these services. Music storage is a prime target for these services but many, like myself, are using them for storage of other types of files such as work files which can be accessed and used with nothing more than a computer and internet connection, anywhere.

Examples of these cloud storage offerings include Dropbox, Amazon Cloud Drive, Apple iCloud, and Microsoft SkyDrive. I looked at the Google Cloud Service but determined it is only useful with Google Docs.

A more detailed comparison of these services can be found here.

The only differences between the four offerings stem from the amount of free capacity available and how you access your files. For example, my Amazon Cloud Drive as seen from my Firefox web interface:

Figure 1: The Amazon Cloud Drive web interface

The advantage to users for these services is the ability to move and store work files that are immediately available to you from anywhere. This means you no longer have to copy files to a USB stick or worse, email work files as an attachment to your personal email account. The disadvantage of these services are corporate information can easily migrate away from the company security and be managed by a third party the company has no agreement with or understanding of in reference to the third party will respond to eDiscovery requests. Also be aware that ESI, even deleted ESI is not easily removed completely. In a previous blog I talked about the Dropbox “feature” of not completely removing ESI when deleted from the application as well as keeping a running audit log of all interactions of the account (all discoverable information). The Amazon Cloud Drive has the same “feature” with deletions.

Figure 2: The deleted items folder in the Amazon Cloud Drive actually keeps the deleted files for some period of time unless they are marked and “Permanently Deleted”

The big question in my mind is how will corporate counsel, employees and opposing counsel address this new potential target for responsive ESI? Take, for example, a company which doesn’t include public cloud storage as a potential litigation hold target, doesn’t ask employees about their use and or doesn’t search through these accounts for responsive ESI…potential spoliation.

For Corporate counsel:

  1. Be aware these types of possible ESI storage locations exist.
  2. Create a use policy addressing these services. Either forbid employees from setting up and using these services from any work location and equipment or if allowed be sure employees acknowledge these accounts can and will be subject to eDiscovery search.
  3. Audit the policy to insure it is being followed.
  4. Enforce the policy if employees are not following it.
  5. Document everything.

For employees:

  1. Understand that if you setup and use these services from employer locations, equipment and with company ESI, all ESI in that account could be subject to eDiscovery review.
  2. If you use these services for work, only use them with company ESI, not personal files.
  3. Be forthcoming with any legal questioning about the existence of these services you use.
  4. Do not download any company ESI from these services to any personal computer, this could potentially open up that personal computer to eDiscovery by corporate counsel

For opposing counsel:

Ask the following questions to the party being discovered

  1. Do any of your employees utilize company sanctioned or non-sanctioned public cloud storage services?
  2. Do you have a use policy which addresses these services?
  3. Does the policy penalize employees for not following this use policy?
  4. Do you audit this use policy?
  5. Have you documented the above?

These services are the obvious path for employees to utilize over the next couple of years to make their lives easier. All involved need to be aware of the eDiscovery implications.