MessageLabs FAQ - Email AntiSpam Service

Spam is unsolicited e-mail sent to a large number of addresses, usually for a commercial purpose. Most spam is commercial advertising, usually for dubious products, get-rich-quick schemes, or quasi-legal services. Often the products advertised are worthless, deceptive, and partly or entirely fraudulent. Other times, it is simply advertising for something that you may not be interested in.

Phishing is the process of luring unsuspecting Internet users to a fake website by using authentic-looking email with the real organisation's logo, in an attempt to steal passwords, financial or personal information, or introduce a virus.

An open relay, also known as 'third party relay' or 'insecure relay', is where a mail server will route email for anybody in the world. Any machine that will accept email for any domain and forward it on regardless of who the sender is or what IP address the email is sent from is generally called an 'open relay' . Spammers hunt for and abuse these servers to try to cover their tracks. When spammers locate such a machine, they can use it as a free distribution service for their junk email.

A whitelist is a list of emails, domains or IP addresses from which you will always accept email, even if it would otherwise be considered spam. For example, newsletters you subscribe to.
A blacklist is a list or of emails, domains or IP addresses from which you will never accept email even if it is otherwise legitimate.

There are two types of spam filter, one that blocks known spam and another that blocks new or unknown spam. Many anti-spam companies like Symantec Brightmail use honey pots, or fake email address to collect spam and create filters to stop that spam. MessageLabs uses Brightmail as one of its filters. For unknown spam, a heuristic algorithm is often used. It checks the structure of the email itself, how many people it is sent to, if it has links, phone number, and so on. Based on these factors, the algorithm decides is this email is spam or not. MessageLabs uses [window u>Skeptic to identify such spam.

DOS is an attack designed to bring the network down by flooding it with requests and traffic. A mail or web server can only handle a finite amount of requests and will crash once that limit is reached.

A variation on DOS is Distributed DOS, where a few to thousands of computers at various locations are part of a coordinated attack on a network.

It is an instance that is erroneously reported as being negative — that is, a spam email which is erroneously reported as not being spam.

It is a negative instance that is erroneously reported as being positive — that is, a non-spam email which is erroneously reported as being spam.

This is a list of email addresses from which email is blocked from being received into the recipient’s inbox. A user may have been enabled to manage a personal blocked senders list. There may also be public and company block lists in place. Quarantine Administrators can view and manage a user’s personal blocked list.

They are recognised public block lists of IP addresses of globally known sources of spam.

An approved senders list that you can specify at either global, group, and user level (depending on your organisation’s configuration). The list can contain email addresses, domains, or IP addresses. The list enables email from a sender on list to pass through the spam service without interruption.

You can check whether your IP address has been blacklisted or not with the following sites:
[window u>CBL]
[window u>SBL]
[window u>Spamcop]
[window u>DSBL]

They are proprietary and commercially available signature-building engines that create a vast knowledge base of signatures of spam messages currently in email circulation.

MessageLabs uses a local component – known as the Client Site Proxy (CSP) to perform authentication against the customer’s Active Directory Environment. All requests are proxied through the CSP which adds the AD information (user name) and local IP in the form of an encrypted x-header for the MessageLabs service to apply policy and perform logging.

Like spam they are unwanted messages sent indiscriminately to many recipients, but over Instant Messaging (IM) networks.

All MessageLabs services are based on a per user, per month subscription, plus a one-off minimal set-up fee.

You simply pay a fixed monthly cost based on the number of users connected. Each service can be purchased separately or you can bundle multiple services to provide complete security protection.

All pricing quotes are individually tailored for each client’s specific requirements and MessageLabs offers discounts for both scale and multiple services.

To find out more, speak with a sales consultant.