Spam filters come in many forms. Appliance-based solutions employing conventional filtering technology can be purchased and maintained on premise and are a popular solution often found in large enterprises.

“Challenge Response” solutions automatically require new outside senders to verify their identity the first time they initiate an email to a protected recipient. While some business customers gravitate to challenge response solutions, there are inherent drawbacks that make them prohibitive for many.

The most common filters are subscription-based spam filtering solutions that are hosted in the cloud and employ conventional spam filtering technologies, in addition to optional, enhanced features.

Cloud-Based Filtering

With rare exceptions, businesses overwhelmingly opt for conventional cloud-based solutions. Cloud-based spam filtering solutions offer a significant advantage in that spam is filtered before it reaches the recipient’s server. Studies have shown that an estimated 85% of email traffic is spam, so for organizations that maintain their own email servers, this advantage is invaluable because it eliminates the burden on the recipient’s mail server, since messages identified as spam never reach the recipient’s server.