User guide

Using VStream Antispam
Chapter 15: Using Antivirus and Antispam Filtering 525
Updating VStream Antivirus
When you are subscribed to the VStream Antivirus updates service, VStream Antivirus
virus signatures are automatically updated, keeping security up-to-date with no need for
user intervention. However, you can still check for updates manually, if needed.
To update the VStream Antivirus virus signature database
1. Click Antivirus in the main menu, and click the Antivirus tab.
The VStream Antivirus page appears.
2. Click Update Now.
The VStream Antivirus database is updated with the latest virus signatures.
Using VStream Antispam
The Safe@Office appliance includes VStream Antispam, an embedded antispam engine
that scans emails for spam. VStream Antispam is composed three antispam engines, each
of which can be enabled or disabled separately:
• IP Reputation
The IP Reputation engine protects mail servers by checking the email sender’s IP
address against an online and constantly updated IP reputation database, before
accepting the SMTP email connection. If the IP address belongs to a known spammer,
the connection can be immediately blocked at the TCP connection level, thereby
stopping the spam before it reaches your mail server.
Note: If you have a mail server in your network, it is recommended to enable the IP
Reputation engine as a first line of defense for incoming SMTP connections. When
enabled, the IP Reputation engine blocks emails that would otherwise reach your
mail server and require extensive analysis by the Content Based Antispam and
Block List engines, both of which examine email content and consume network,
gateway, and mail server resources. By reducing the amount of emails that require
in-depth analysis, the IP Reputation engine helps prevent Denial of Service (DoS)