Email Security

Unlike most spam filtering solutions, which use one or two spam-classification techniques, MailStreet Premium Anti-spam aggregates the most effective spam filters and techniques in the industry, currently leveraging the strengths of five spam-fighting filters:

1. Domain-level Black and White Lists

Maintained by the end-user, these customized lists detail sites, individuals, or IP addresses from which mail is or is not allowed. Users can establish white/black list entries using wild-cards (*@domain.com), IP address, or email address. Lists can also be imported via ASCII text file. White/Black lists can be established at a per-user level, or across the entire domain.

2. Distributed Black Lists

Mail Abuse Prevention Services (MAPS) is a real-time subscription service that maintains multiple lists of known spammers to help gauge the likelihood of a message being spam.

3. Bayesian

Statistical algorithms identify and quantify the possibility that an email message is spam.

4. Heuristics

Thousands of proprietary rules of thumb recognize characteristics of spam.

5. Distributed Checksum Clearinghouses

Takes a checksum, or fingerprint, of all email messages it sees and places those fingerprints in a database. If the database recognizes a large number of exact matches, or at least very similar fingerprints, then those fingerprints are likely to indicate spam.

Each of our five filters dynamically calculates the spam probability of every message. Through an aggregation and analysis of these spam-likelihood scores, our patent pending, multi-layered spam detection system provides extremely effective spam blocking.

Messages with high spam probability scores are either quarantined (default behavior) or you may choose to prefix these messages with a subject of "[SPAM]" or deny delivery altogether.

In addition to the state-of-the art spam filtering offered by MailStreet Premium Anti-spam, organizations have the ability to apply the following filters to further protect the inbox:

Attachment Guard

Allows domain admistrators to create attachment polices. For example, allow only ".doc" files and block all ".zip" files, etc.

Content Filter

Content filters allow you to filter out messages containing various content keywords. You can choose from pre-configured content lists containing profanity or racially insensitive keywords, or create your own list. Messages that violate these filters can be either tagged, quarantined, or denied.

HTML Shield

HTML Shield allows you to remove all malicious HTML tags (iframe, frame, layer, span, meta, style), disable all Javascript/Java/ActiveX (script, style, embed, object, applet), and/or remove HTML comments and attributes from incoming messages.

Recipient Shield

With Recipient Shield, you can block all traffic sent to any address on your domain.

Exempt Users

You may also opt to exempt certain email adresses from the MX filtering. Addresses entered in the exempt user list will not be filtered, and will instead be delivered immediately to the user's inbox.

The advanced email filtering provided by the Premium Anti-spam service experiences virtually no delivery delays.

Leveraging a "pod" (N+1) architecture with multiple data centers, Email Defense service provides carrier-class availability of filtering and delivery components. Messages traverse the network and transparently pass through complex filtering layers without latency. Sub-second processing provides for almost no delay as messages are "proxy-streamed" into the enterprise.

Users receive a daily "Spam Summary Report" that enables each user to release, allow, or deny delivery of quarantined messages to their inbox.

Additionally, administrators may choose from the following reporting features:

• Threat Overview
• Traffic Overview
• Threats: Spam
• Threats: Content
• Threats: Attachments
• User Activity
• Event Logging

Layering technology is the key to protecting your organization against email threats—especially when it comes to viruses and worms. Premium Anti-spam Critical Defense provides an additional, complementary layer of protection to a company's on-premise anti-virus engine—identifying, quarantining, blocking, and stripping viruses and worms at the network perimeter—before they enter or leave the messaging infrastructure. While a single anti-virus installation can provide reasonable resistance from known and unknown viruses, the protection of multiple, complementary engines can dramatically reduce the risk of infection and provide an increased ability to stop new strains before they are recognized by a single scanner. Additional lowering of risk is applied by leveraging each engine's organic technology for behavior analysis of execution intent, and associated heuristics for detection of unknown and new virus strains.