Evaluate the pros and cons of various email archiving solutions
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.