# Anti-Spam Overview

The IMail Server anti-spam features pass messages through several layers of filters and tests to assure that maximum spam detection is achieved. Messages are compared against DNS black lists, spam word statistics, a configurable spam phrase list, and undergo HTML filtering. You can also force messages to pass connection verification checks which verify the "Mail FROM" address, HELO/EHLO domain information, and perform a reverse DNS lookup.

Basic Setup Tasks

To set up the basic IMail Anti-Spam configuration, complete the following steps:

Configure DNS Black Lists for the Server

Enable DNS Black Lists for the Host

Enable and Configure Phrase Filtering

Enable and Configure Statistical Filtering

Configure Trusted Addresses/Domains

Configure HTML Feature Filtering

Create a URL Domain Black List

## Configurable for Each Domain

DNS black lists are configured and enabled at the server level. Host administrators can then choose which black lists to enable for the host. All other anti-spam options are controlled by each host that has a valid IP address. Thus, each host can use different DNS black lists, trusted addresses, phrase lists, URL Domain black lists and define their own statistical filtering and HTML feature filtering configurations.

## Spam Actions

If a message is identified as spam, you can delete it, forward it to an e-mail address, move the message to a mailbox,or insert an X-header in the message to identify which spam test it failed. You can also create delivery rules to search for the spam X-Headers and process the message accordingly.

## Accessing the Anti-Spam Pages

The Anti-Spam Options page is accessed by selecting Anti-Spam Admin from the Account Options drop down box. This link is only available to host or system administrators.

The other anti-spam pages can only be accessed by users who have specific account privileges. Host administrators can access the Host Black Lists, Host Black List Entry, Phrase Filtering, Statistical Filtering, HTML Feature Filtering, Trusted Addresses and URL Domain Black List pages and help topics. System administrators can access the Server Black Lists and Server Black List Entry pages and help topics.

## Changing Domains

The IP Domain list box, located at the top of all anti-spam pages, displays the domains for which you can configure anti-spam options (hosts with IP addresses). You can switch easily between hosts by selecting the host name from this list box. When making modifications to any anti-spam options, make sure that the correct host is displayed in the IP Domain list box.

Note: Hosts without IP addresses will not be displayed in this list box.