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How to evaluate Exchange Server archiving products

To help you find the right e-mail archival product for your Exchange Server environment, this article describes some important features to look for and provides questions to ask when comparing products.


To help you find the right e-mail archival product for your Exchange Server environment, this article describes some important features to look for and provides questions you can ask when comparing products. You'll still need to do your homework and test products carefully, but this article will help you more quickly identify features most important to your organization's needs.

Migrating messages and attachments

The majority of e-mail archival solutions have a feature that can reduce total Exchange Server storage by replacing e-mail messages (and attachments) with small "stub" files. Attachments are a particular storage burden to Exchange. By migrating large messages and attachment files to an archive, Exchange storage can be dramatically reduced, while users continue to have access via Microsoft Outlook.

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When comparing e-mail archival products, carefully review what impact the migration job has on Exchange Server and how the migrated messages are accessed. Here are some questions you should consider:

  • What policy and control settings migrate messages (and attachments)?
  • Is a migration agent required on Exchange Server?
  • When is the migration job run (daily, weekly, etc.)?
  • Can the migration job be broken into smaller jobs? (This is important when you have thousands of mailboxes to manage.)
  • Does the migration job replace message and/or attachments with stubs?
  • How do users access the migrated messages (and attachments)?
  • Can users view the migrated message (and attachment) via Microsoft Outlook without restoring to Exchange Server?
  • Can migrated messages (and attachments) be converted back to their original form?

Managing .PST files

Using a manual or automated process, e-mail archival products can copy existing .PST file data into an archive, where it is centrally protected and accessible for search and discovery. When comparing the .PST archive feature, be careful to review how the .PST files are migrated and how they are accessed afterward. Here are some questions to guide your review:

  • Can users manually archive .PST data into the archive?
  • After migration, how are the .PST files deleted or removed?
  • Can administrators schedule .PST archival using an automated process (PST Crawler)?
  • Are any "stub" files placed in Exchange Server for access to the .PST archive data?
  • How do users access the .PST archive data?
  • Can archived .PST data be converted back to its original form?


Archiving e-mail for compliance refers to 100% capture of e-mail data to satisfy regulatory requirements and/or for legal discovery and litigation support. The standard for 100% e-mail capture on Microsoft Exchange is a feature called Journaling. When Journaling is enabled on Exchange Server (per mailbox store), all incoming and outgoing e-mail is copied to a journal mailbox where it is held for subsequent reading by an e-mail archive product.

The drawback of Journaling is the performance impact it has on Exchange. Journaling effectively doubles the workload on Exchange Server; careful planning is necessary to avoid a drop in overall Microsoft Exchange performance when using this feature.

When comparing e-mail archival solutions, be careful to ask how e-mail is archived for compliance, and if journaling is required. Some new e-mail archival solutions offer alternatives to journaling that promise to capture 100% of e-mail without the performance impact of journaling.

  • How is 100% of e-mail data captured for compliance?
  • If Journaling is required, what is the performance impact on Exchange Server?
  • Is an agent required on the Exchange Server?
  • How often is the journal mailbox read?
  • Is the journal mailbox emptied after it is read?
  • Does the journal mailbox data include message folders? Contacts? Calendar?


In this article, we discussed three major features of e-mail archival and listed sample questions for each. These e-mail archival features were selected because of their complexity and the potential impact they can have on Exchange Server performance.

E-mail archival products differ widely by design and to the extent they impact Exchange performance. As you prepare your shopping list for e-mail archival solutions, consider carefully your Exchange Server growth demands -- a proper e-mail archival solution will grow and scale with Exchange and not become a performance burden.

About the author: Bob Spurzem is Senior Product Marketing Manager for Mimosa Systems Inc.


We recently began implementing an archival product called Archive Attender (Sherpa Software) mostly because it was inexpensive. Although the product offers the ability to stub messages, we chose not to use that feature since we have so many pack rats, with tens of thousands of items in their default folders. Our assumption was that, even if we were able to reduce our storage by 70%, we'd still have millions of index entries to manage, which we figured played a major role in our rapidly declining performance.

In your opinion, what is the biggest factor in performance between size of databases/stores and the number of items stored?
—Rob S.


You raise an important question about the performance of Exchange Server (and Microsoft Outlook) when the number of messages gets quite large.

Email archive solutions that create stub files for online email and offline email (.PSTs) can add thousands of entries into Microsoft Outlook and slow its overall performance. (For more information, refer to this recent blog from the Exchange development team on email archiving. )

When your message count for online email exceeds 2,500 to 5,000 per folder, consider removing email entirely from the Exchange server and rely on the copy in the archive. For offline email (.PSTs), some email archive solutions archive the .PST data and do not put "stubs" in Exchange. This is desirable because it avoids the issue you have identified.

When configured properly, email archive solutions should take the load off Exchange Server (including no stub files) and be able to archive years of email.
—Bob Spurzem, tip author

Do you have comments on this tip? Let us know.

Related information from SearchExchange.com:

  • Article: Poll reveals IT managers' e-mail archiving concerns
  • Tip: E-mail archiving shopping tips
  • Ask the Expert: The difference between backups and archives
  • Reference Center: Exchange Server archiving tips and resources
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