Anti-Spam; Chapter 32 Anti-Spam; Overview; What You Can Do In This Chapter - ZyXEL Communications ZYWALL USG 20 Manual

C
H A P T E R

32.1 Overview

The anti-spam feature can mark or discard spam (unsolicited commercial or junk
e-mail). Use the white list to identify legitimate e-mail. Use the black list to
identify spam e-mail. The ZyWALL can also check e-mail against a DNS black list
(DNSBL) of IP addresses of servers that are suspected of being used by
spammers.

32.1.1 What You Can Do in this Chapter

• Use the General screens
and manage anti-spam policies.
• Use the Black/White List screens
list to identify spam and a white list to identify legitimate e-mail.
• Use the DNSBL screens
e-mail against DNS Black Lists.

32.1.2 What You Need to Know

White list
Configure white list entries to identify legitimate e-mail. The white list entries have
the ZyWALL classify any e-mail that is from a specified sender or uses a specified
header field and header value as being legitimate (see
522 for more on mail headers). The anti-spam feature checks an e-mail against
the white list entries before doing any other anti-spam checking. If the e-mail
matches a white list entry, the ZyWALL classifies the e-mail as legitimate and does
not perform any more anti-spam checking on that individual e-mail. A properly
configured white list helps keep important e-mail from being incorrectly classified
as spam. The white list can also increases the ZyWALL's anti-spam speed and
efficiency by not having the ZyWALL perform the full anti-spam checking process
on legitimate e-mail.
ZyWALL USG 20/20W User's Guide
(Section 32.3 on page
(Section 32.4 on page
(Section 32.6 on page 532) to have the ZyWALL check
32

Anti-Spam

523) to turn anti-spam on or off
527) to set up a black
E-mail Headers on page
521