Skip navigation

Hosted Versus On-Premises Email Archiving

Evaluate the pros and cons of various email archiving solutions

Some topics are polarizing by their very nature. For example, if you ask a random person about a reality TV show such as So You Think You Can Dance, you'll likely get one of two responses: The person will either love the show or hate it. Email archiving fosters the same kind of polarized reaction. People who work for organizations that have archiving and compliance requirements are intensely interested in the topic, whereas people who work for organizations that don't have such requirements typically pay little or no attention to archiving.

However, this polarization is slowly changing as more organizations realize the benefits of archiving corporate email messages. These advantages include ease of compliance with regulatory requirements and improved productivity for end users who benefit from having all their mail available at once.

Microsoft has been fairly aggressive in the archiving space, introducing its own on-premises archiving solution in the form of Exchange Server 2010's Personal Archive feature. Exchange 2010 SP1 allows a mailbox and its associated archive to be in different mailbox databases, which means your mailboxes can be hosted by Microsoft Office 365 and your archives can be hosted on your own servers, or vice versa. Several archiving vendors also sell their own hosted archiving systems. Evaluating the pros and cons of each type of archiving system will help you understand the benefits and drawbacks of each, so that you can determine how a particular solution might meet your own needs.

Do You Need Archiving?

The first question to ask is whether you actually need archiving in the first place. There are three possible answers to this question: Yes, No, and Maybe.

Some companies are required by law, regulation, or other considerations to maintain archives of their email messages. Examples abound; for example, financial services companies in most countries are required to archive at least some of their electronic communications, and many choose to go beyond the basic requirements to reduce their liability.

A small number of companies absolutely do not want to use archiving because they don't want a corporate-sponsored repository of valuable data that becomes subject to legal discovery or regulatory inquiry. To the extent that they're required to use archiving for regulatory or compliance reasons, they aggressively limit what they archive, how long it's kept, and who's allowed to set or change archiving policies.

Most companies fall between these extremes. They don't have a defined legal or regulatory requirement to archive their email messages. Instead, they might archive messages to reduce the cost of messaging services, to prepare for potential discovery or compliance requirements in the future, or to improve employee efficiency by giving users a robust archiving mechanism. Organizations in this group can often categorize the demand for archiving based on the stakeholders who are asking for it:

  •  IT stakeholders are primarily concerned with cost reduction, data management, and service provision. If you're asking questions such as "Will archiving help extend the useful life of my servers?" and "Can archiving reduce the cost of my primary Exchange storage?" then you fall into this category.
  • Business stakeholders are primarily concerned with efficiency and productivity. For them, archiving is a way to help users be more productive by allowing fast recovery of required data.
  • Legal stakeholders are typically tasked with keeping the organization and its employees out of jail and out of the headlines. Their archiving requirements involve the ability to quickly and accurately respond to discovery requests, dispose of unneeded data, and set policies that ensure that the requirements they face are met consistently.

Because of the overlap between these requirements, you might think that selecting an archiving solution would be straightforward. In practice, what typically happens is that Exchange administrators are asked to choose a solution based on their own understanding of the requirements -- which often leads to buying an inappropriate solution. If archiving is important to your business, you must think of it as a long-term strategy, not a check box or a purchase order.


On-Premises Pros and Cons

The market for on-premises archiving solutions is mature because archiving solutions have been around nearly as long as email server products have. As email infiltrated the financial services, pharmaceutical, and government sectors, customers demanded robust archiving solutions -- so major archiving vendors have had years to build solutions. In fact, the market has evolved to the point where email archiving itself is only a small part of most products' feature sets. For example, it's common for archiving products to provide tools for ingesting unstructured data such as file shares and Microsoft SharePoint libraries, integration with case and litigation management systems, and other bells and whistles that go beyond basic archival and e-discovery features.

The major advantage of on-premises archiving is that you're in complete control. You have both complete authority and complete responsibility. You get to choose what's archived, where it's stored, who has access to it, and so on. However, if problems develop with the archive, there's nowhere to point the finger of blame. For example, if you're required to perform a discovery search as part of a court case and you can't produce all the necessary records, you probably won't be able to blame the vendor.

You should also keep in mind that a high degree of control also requires a high degree of operational maturity and experience. Even the best-designed, easiest-to-use systems require some administrator time -- and a poorly designed or complex system requires that much more. If you don't have the time or in-house knowledge required to manage a full-blown on-premises archiving system, then a hosted offering might be a better choice.

Another advantage of on-premises archiving is that on-premises systems tend to have much greater functionality than hosted systems. On-premises systems can ingest and manage more types of data, given the fact that most organizations don't want to make all their data externally accessible to hosted archiving tools. In addition, on-premises systems provide tighter integration with a wider variety of back-end systems -- and many of them provide customization capabilities as well. In general, if you need to archive SharePoint, file server, or other types of data besides email, you probably need an on-premises solution.

The pros and cons of on-premises solutions are more mixed when it comes to cost. You typically must purchase the entire archiving system up front, which means that for most organizations, archiving is initially funded as a capital expenditure rather than from operating funds. The need to purchase all the services you require means that it's somewhat more difficult to deploy pilot programs with on-premises systems, because you must buy all the major components in order to get even a single mailbox archived -- which can be a major barrier to adoption unless you're absolutely certain which archiving product you want to deploy.

Hosted Pros and Cons

Hosted services of all kinds share a few common attributes. One is that they tend to offer pay-as-you-go pricing. This makes them attractive to customers who want to be able to predict exact costs for the services they use. Keep in mind, of course, that the hosting provider can (within the limits of whatever contract you negotiate) change the price for archiving services. Many hosting providers price their services according to the amount of archive data you store -- which certainly seems reasonable, although it puts a premium on your ability to estimate how much storage you'll use over the term of your hosted service contract. However, this disadvantage might be small compared with the flexibility of being able to lease or subscribe to the services you need for the term in which you need them.

Another aspect of hosted archiving services that makes them attractive is their ease of deployment. Typically, hosted archives let you feed them your mailbox data over time. Web-based archiving systems let you deploy archive search-and-discovery facilities to users who need them without installing or configuring desktop client software, which is another significant benefit.

Hosted services put the burden of management, maintenance, monitoring, and security on your hosted service provider. If you want "set-it-and-forget-it" archiving capability, hosted solutions can give it to you. It's a good idea to carefully review the archiving provider's service level agreement (SLA), and of course you should thoroughly investigate a hosted archive provider's customer references before signing an agreement. Run -- don't walk -- away from any vendor that makes it difficult for you to do either of these things.


Exchange 2010's Archiving

In your consideration of on-premises archiving systems, be sure to include Exchange 2010's built-in archiving features. Although these features might not be a perfect fit for every organization, they're priced into Exchange 2010 -- which might let you hit some of your archiving requirements with minimal additional expense.

Microsoft has made a lot of noise around its Software Plus Services (S+S) strategy, but Exchange 2010 and Office 365 are a great example of how this strategy can pay off. You can host your mailboxes on your own Exchange servers and store archives on Exchange Online, or vice versa. You have a great deal of flexibility regarding how you manage and operate your mailboxes and where you store your data. Other archiving vendors can't yet match the tight integration between Exchange Online and on-premises Exchange. It's reasonable to expect a continuing movement to more tightly integrate these services (along with the other components of Office 365).

Keep in mind, though, that Exchange's archiving doesn't do everything that larger, more complex archiving products do. Its strengths lie in cost, integration (such as the fact that discovery searches are controlled by Exchange's Role Based Access Control -- RBAC - permissions feature), and ease of deployment. If you have complex discovery requirements, you might find that a third-party solution, whether on-premises or hosted, is a better fit for your needs.


As you evaluate whether a hosted or on-premises solution is best for your environment, you should ask numerous questions. The following five questions are especially important:

1. Why am I archiving? Understanding the business reasons that underlie your archiving requirements is critical to choosing the right combination of products and services. If there are specific laws or regulations that you must meet, you need to know what they are and what they require. Your organization's legal and business stakeholders are important sources to help answer this question.

2. How predictable is my deployment? Do you have good information about how much data you need to archive and how it's likely to grow in the future? Without these figures, you might lean toward a fixed-cost on-premises solution, but with better information you can make a more informed decision about the subscription or lease cost of a hosted solution.

3. Can I handle success? If your archiving system gets more use than expected or requires more administrative time than you plan for, will you have the resources to handle it?

4. How much do I trust my archiving vendor? The archiving marketplace has been undergoing consolidation for the past 2 or 3 years, and that trend appears set to continue. It's important that you're comfortable with your archiving vendor's history of product support, track record for support of new Exchange releases, and road map for supporting on-premises, hosted, and hybrid solutions.

5. What's my roadmap? In other words, what kind of data growth do you expect for all the data types you have to archive? Are there business changes, such as mergers, acquisitions, or entries into new business areas ahead that might change your archiving needs? What about Exchange upgrades and migrations? This question is a great opportunity for you to assess any other future factors that you think might influence your choice of product, hosting mode, or deployment schedule.

If you're not certain of the answers to any of these questions, consider how you could pilot archiving solutions to help provide more fodder for making an informed decision.

The Future of Archiving

The brisk competition between hosted and on-premises services in general is sure to continue. To decide between a hosted and on-premises solution for email archiving, you must understand your archiving requirements and how each type of solution might meet those requirements. As Microsoft begins work on the successor to Exchange 2010, and as archiving vendors continue to merge and consolidate, expect to see significant changes in this space within the next 2 or 3 years.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.