Quick Reference Guide

Chapter 3. Performing Network and System Management | 83
ProSecure Web/Email Security Threat Management (STM) Appliance
You can adjust the following features of the STM in such a way that the traffic load on the
WAN side decreases.
• Email content filtering. To reduce incoming email traffic, you can block emails with large
attachments, reject emails based on keywords, file extensions, or file names, and set
spam protection rules. There are several ways you can reduce unwanted email traffic:
- Setting the size of email files to be scanned. Scanning large email files requires
network resources and might slow down traffic. You can specify the maximum file or
message size that is scanned, and whether files that exceed the maximum size are
skipped (which might compromise security) or blocked. For more information, see
Exception Settings on page 90.
- Keyword, file extension, and file name blocking. You can reject emails based on
keywords in the subject line, file type of the attachment, and file name of the
attachment. For more information, see Email Content Filtering on page 94.
- Protecting against spam. Set up spam protection to prevent spam from using up
valuable bandwidth. For more information, see Protecting Against Email Spam on
page 97.
• Web content filtering. The STM provides extensive methods to filter Web content in
order to reduce traffic:
- Web category blocking. You can block entire Web categories because their content
is unwanted, offensive, or not relevant, or simply to reduce traffic. For more
information, see Configuring Web Content Filtering on page 109.
- File extension blocking. You can block files based on their extension. Such files can
include executable files, audio and video files, and compressed files. For more
information, see Configuring Web Content Filtering on page 109.
- URL blocking. You can specify URLs that are blocked by the STM. For more
information, see Configuring Web URL Filtering on page 116.
- Web services blocking. You can block Web applications such as instant messaging,
media, peer-to-peer, and tools. For more information, see Configuring Application
Control on page 127.
- Web object blocking. You can block the following Web component types: embedded
objects (ActiveX, Java, Flash), proxies, and cookies; and you can disable Java
scripts. For more information, see Configuring Web Content Filtering on page 109.
- Setting the size of Web files to be scanned. Scanning large Web files requires
network resources and might slow down traffic. You can specify the maximum file size
that is scanned, and whether files that exceed the maximum size are skipped (which
might compromise security) or blocked. For more information, see Configuring Web
Malware Scans on page 107.
For these features (with the exception of Web object blocking and setting the size of files
to be scanned), you can set schedules to specify when Web content is filtered (see
Configuring Web Content Filtering on page 109) and configure scanning exclusions and
access exceptions (see Setting Scanning Exclusions and Web Access Exceptions on
page 130). You can use the STM’s monitoring functions to assist you with performance
management (see Monitoring Real-Time Traffic, Security, Statistics, and Web Usage on
page 184).