Anti-Spam Technical Reference - ZyXEL Communications ZyWall USG 2000 User Manual

The following table describes the labels in this screen.
Table 175 Anti-X > Anti-Spam > Status
LABEL
Refresh
Flush
Concurrent Mail
Session Scanning
DNSBL Statistics
#
DNSBL Domain
Total Queries
Avg. Response
Time (sec)
No Response

35.8 Anti-Spam Technical Reference

Here is more detailed anti-spam information.
DNSBL
• The ZyWALL checks only public sender and relay IP addresses, it does not check
private IP addresses.
• The ZyWALL sends a separate query (DNS lookup) for each sender or relay IP
address in the e-mail's header to each of the ZyWALL's DNSBL domains at the
same time.
• The DNSBL servers send replies as to whether or not each IP address matches
an entry in their list. Each IP address has a separate reply.
ZyWALL USG 2000 User's Guide
DESCRIPTION
Click this button to update the information displayed on this screen.
Click this button to clear the DNSBL statistics. This also clears the
concurrent mail session scanning bar's historical high.
The darker shaded part of the bar shows how much of the ZyWALL's
total spam checking capability is currently being used.
The lighter shaded part of the bar and the pop-up show the historical
high.
The first number to the right of the bar is how many e-mail sessions
the ZyWALL is presently checking for spam. The second number is the
maximum number of e-mail sessions that the ZyWALL can check at
once. An e-mail session is when an e-mail client and e-mail server (or
two e-mail servers) connect through the ZyWALL.
These are the statistics for the DNSBL the ZyWALL uses. These
statistics are for when the ZyWALL actually queries the DNSBL
servers. Matches for DNSBL responses stored in the cache do not
affect these statistics.
This is the entry's index number in the list.
These are the DNSBLs the ZyWALL uses to check sender and relay IP
addresses in e-mails.
This is the total number of DNS queries the ZyWALL has sent to this
DNSBL.
This is the average for how long it takes to receive a reply from this
DNSBL.
This is how many DNS queries the ZyWALL sent to this DNSBL
without receiving a reply.
Chapter 35 Anti-Spam
589