Because they have central control of e-mail for all their users, IT departments can tackle spam at the server level, where a twist or two on a single valve can greatly diminish the flow.
Here are some of our favorite products and services:
Subscription services
The best solution is to stifle spam in transit. There are two good ways to do that. First, you can subscribe to a service that blocks spam before it gets to your mail servers. To identify which messages are spam, these services set up accounts that serve only as spam-bait. Any messages received by these accounts are flagged to be filtered by agents on customers' networks. Anti-spam services typically cost a few dollars per user mailbox per year. See subscription services product table.
Server-based software
There are also server-based software products that act as gateways against unwanted messages. Running on the mail server or a separate machine, they check e-mail header and transport information and block invalid messages and those from known spammers. These products may be priced on a per-mailbox or per-server basis.
Many of these products can refer to a list of known spammers and screen them out. The most popular list is Mail Abuse Prevention Systems' (MAPS) Realtime Blackhole List. MAPS blocks spammers by removing their service providers' addresses from its domain name servers. The filtering products check the header information of an incoming message against MAPS's domain servers before letting it through. See server-based software product table.
Hardware gateways
If you have a very high volume of incoming mail, you may benefit from a hardware-based e-mail screening gateway. Its only advantage over a software-based product is the ability to handle a higher volume of messages. Such appliances, which generally cost less than $5,000, sit between your router and mail servers and filter unwanted messages. See hardware gateways product table.
Last line of defense
The final line of defense is the individual client. Teach users how to implement rules or filters in the e-mail client your organization uses, or download any of the popular anti-spam programs. But don't rely solely on client products, because they're difficult to manage and easily disabled by users. If you don't want your employees to receive spam in the first place, make a firm policy that employees can only use their company e-mail addresses for company business.
If you're looking for more options, the SpamCon Foundation has a nice list of products and services that handle this task, along with many other resources to help you fight spam.
The upside of all this processing is an inbox free from unwanted distractions, which allows your users to focus on more productive tasks, and a server with more free disk space, but there's a downside as well. Sometimes filters think real messages are spam because of their origin or the subject line. Some products let users set up a special folder for screened messages so they can make sure the screening software is not deleting anything vital.
If you succeed in diminishing the volume of spam flowing to your users' mailboxes, congratulate yourself. You've eliminated one big headache for everyone.
What does your company do to fight spam--and does it work? Share your thoughts in Talkback below or e-mail us.
