written by: Lee Clemmer•edited by: Bill Bunter•updated: 7/6/2011
It may seem like ordinary Internet users bear the brunt of email spam, but businesses may be an even bigger victim. With so many email addresses present in single domains, and with email addresses for sales, support, and other functions readily available, businesses are a big & easy spam target.
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Business' Anti-Spam Burden
Spam, or unsolicited commercial email (UCE) is a constant burden for corporate Internet email servers and gateways. Fortunately, businesses usually have the ways & means to apply effective anti-spam technology. Automated spamming, once it has your company's email domain as a target, can be like a denial of service (DoS) attack on your mail servers. Let's look at the top five ways businesses can combat spam.
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5. Use a Separate Internet Email Gateway
For a large or enterprise businesses, separate gateways and routing for Internet email are already part of the architecture. Even for smaller organizations this can be a benefit, both for performance and for anti-spam purposes. Spamming attempts can put a load on servers, and real-time filtering performs better when separated from internal messaging.
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4. Content Filtering Stops Spam
Much of the spam contains content that your company Internet use policy may prevent anyway. Tie in the content filtering capabilities you have available to block unauthorized content just like for web access, and much of the spam may be removed purely by this method. Most modern content filtering solutions can filter email as well as web content.
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3. Client Spam Reporting Improves Filtering
When spam does get through, if the first email client and user to see it can update the anti-spam database, that may be able to subsequently filter the spam and prevent it from reaching any or all other users. Use a client-side anti-spam component that allows user updates to the spam filtering database.
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2. Use Modern & Heuristics-based Filtering
Modern anti-spam filtering techniques use a mixture of different methods to catch spam. The best spam blocking goes far beyond blacklisting of known spam. Filters scan the content and structure of messages using advanced algorithms to filter on more than just key words, phrases, or other content. This is one of the most effective means of filtering. Anti-spam solutions use online, updated databases of spam information, allowing others to benefit from their identification of spam messages and sources. Combining these methods gains the maximum spam prevention effect.
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1. Filter at the Firewall or a Dedicated Appliance
Anti-spam technology can be integrated into your firewall, or placed inline on the network on an appliance. This takes the burden off your email servers, and distributes the load of spam filtering. Appliances designed to block spam can perform better than a server alone. Moving the point of filtering to the edge of the network also is a strong design principle.