Categories: Security
      Date: Sep 10, 2010
     Title: Reasons to Consider Hosted Spam Filtering
You might have been considering implementing a {cms_selflink page='home' text='hosted spam filtering '} solution such as {cms_selflink page='email-filtering' text='Your Clean Mail'} service, but are unclear as to how it works, and what reprecussions it might have on your existing IT infrastructure....

You might have been considering implementing a {cms_selflink page='home' text='hosted spam filtering '} solution such as {cms_selflink page='email-filtering' text='Your Clean Mail'} service, but are unclear as to how it works, and what reprecussions it might have on your existing IT infrastructure.

Simply put, the majority of hosted or cloud-based spam filtering works by redirecting incoming e-mails directly to the appointed service provider instead.  This is achieved by appropriately modifying the IP address listed under the MX configuration of the company’s domain. As a result, e-mails that come in are forwarded to the service provider’s servers first, before being rerouted to the “real” e-mail server.

Today, I’ve listed some important factors of a hosted spam filtering deployment that the technical manager will be interested in.

Freedom from the burden of processing spam

One of the key advantages of using a hosted provider to tackle spam is how it allows businesses to offload the computational and storage demands of eliminating spam to a service provider.  Unlike the hard to predict costs of operating and maintaining servers over any length of time, hosted spam filtering providers charge a fixed rate per protected mailbox, which serves to eliminate hidden or unanticipated costs.  Ultimately, this allows businesses to better track and budget for the cost of properly equipping each employee in the company.

Bandwidth and DDOS protection

One facet that is usually missed out in a hosted spam filtering deployment is the greatly reduced bandwidth required for the e-mail server.  Assuming the company e-mail server is hosted in a data centre, this translates into direct savings on the billable bandwidth since only e-mails that have been cleaned are forwarded to the mail server.  This reduction in network traffic is true even in servers deployed on the local area network and which will be evidenced by faster Internet connectivity in the office.

In addition, the use of a hosted spam filtering service also grants an implicit defence against denial of service attacks that are propagated against the e-mail domain.  Obviously, this does not stop a malicious hacker or entity from directly targeting your e-mail server’s IP address.  It does however form an additional layer of defence against DDOS, and should be more than adequate against casual or widely targeted spamming.

Platform Neutrality

One of the greatest advantages of a hosted spam filtering service is its platform neutral nature. All messaging systems are supported by default, ranging from Microsoft Exchange, Lotus Notes, to standard POP or IMAP servers.  This includes more sophisticated deployments involving BES implementations of BlackBerry smartphones or Exchange Sync clients like the iPhone.

The only real prerequisite to use hosted spam filtering is that the protected e-mail address must belong to a company-owned and managed domain, in order to allow the MX configuration to be modified accordingly.  E-mails flowing in will be automatically forwarded to the service provider, which will eventually route processed e-mails back to the correct e-mail server.

Ease of deployment

All it takes is a signed service contract and the appropriate modification of MX records to enable hosted spam filtering, making it a trivial matter to implement.  The reverse is true of a self-deployed solution; companies usually have to either acquire physical severs (or provision virtual ones), purchase the correct number of client access licenses, followed by the installation and configuration of the appropriate spam filtering software.  And I’ve not even got started about setting up the appropriate level of failover redundancy or the training and lead time required of the technical staffers running it on a day-to-day basis.

On the other hand, hosted spam filtering can be implemented without extraneous training for already overwhelmed IT managers or system administrators.  In fact, the correct information and authorization to modify the MX records could even allow service providers to setup and enable their service – remotely.

Flexible and versatile

Finally, the nature of hosted spam filtering allows for great flexibility and versatility in how it is deployed.  For example, users can concievably “stack” multiple providers in a chain, or opt to channel e-mails through another server (or service provider) for archival first, or even reroute new e-mails to a different server for the purpose of rolling out a new e-mail server.  The list goes on.

This clean separation between the various components of your e-mail subsystem means there is no need for corporations to be concerned about operating system security patches or updates to the spam filtering software inadvertently “breaking” any part of your precious e-mail infrastructure.

By Paul Mah (