Unless your law firm’s email addresses are anything less than brand-shiny new, some of your email undoubtedly will be spam. Until there are fundamental changes in how the Internet is managed (including the use of Simple Mail Transfer Protocol or SMTP), part of the job of IT staff at any moderately sized law firm will be managing unwanted email.
There are many products and tools designed to help with this and there are many things to consider when choosing one of them. Does your law firm only require in-bound spam filtering or does it also need out-bound smart host services? If the latter, which ones? Do you prefer the ease of a managed hosted solution or do you want the increased security and potential features of an on-premises software package, appliance or virtual appliance?
The costs and benefits of hosted versus on-premises solutions parallel those in other areas. The pricing for each will have to be evaluated separately with an eye towards your business needs.
The initial cost of implementing an on-site solution will be higher than one hosted in the cloud, since equipment and software will have to be purchased, leased and/or licensed (and renewed/upgraded over time). Installation will take time and maintenance will be an ongoing expense, but, ideally, it would cost less per year than of having the service hosted entirely in the cloud. For cloud services, where you don’t have the need to purchase and configure either hardware or software, the initial outlay is small and setup can be done relatively quickly. Costs also tend to be predictable and spread out over a longer period of time, which may be beneficial from an accounting standpoint.