ZyXEL Communications 5 Series User Manual

 Chapter 16 Anti-Spam Screens

ZyWALL 5/35/70 Series User’s Guide

From, To

Select the directions of travel of packets that you want to check. Select or 
clear a row or column’s first check box (with the interface label) to select or 
clear the interface’s whole row or column. 
You could for example have the ZyWALL check packets traveling in from the 
WAN to the interface your e-mail server is on. For example, From WAN1 To 
DMZ, or From WAN2 To DMZ.
From LAN To LAN means packets traveling from a computer on one LAN 
subnet to a computer on another LAN subnet via the LAN interface of the 
ZyWALL. The ZyWALL does not check packets traveling from a LAN 
computer to another LAN computer on the same subnet.
From WAN1 To WAN1 means packets that come in through the WAN 1 
interface and the ZyWALL routes back out through the WAN 1 interface.
From VPN means traffic that came into the ZyWALL through a VPN tunnel 
and is going to the selected “to” interface. For example, From VPN To LAN 
specifies the VPN traffic that is going to the LAN or terminating at the 
ZyWALL’s LAN interface. The ZyWALL checks the traffic after decrypting it. 
To VPN is traffic that comes in through the selected “from” interface and 
goes out through any VPN tunnel. For example, From LAN To VPN 
specifies the traffic that is coming from the LAN and going out through a VPN 
tunnel. The ZyWALL checks the traffic before encrypting it. 
From VPN To VPN means traffic that comes in through a VPN tunnel and 
goes out through (another) VPN tunnel. This is the case when the ZyWALL 
is the hub in a hub-and-spoke VPN. The ZyWALL checks the traffic after 
decrypting it (before encrypting it again). 

Note: The VPN connection directions apply to the traffic going 

to or from the ZyWALL’s VPN tunnels. They do not 
apply to other VPN traffic for which the ZyWALL is not 
one of the gateways (VPN pass-through traffic). 

Action for Spam Mails

Use this section to set how the ZyWALL is to handle spam mail.

X-Header

An X-Header is a line (preceded by “X-”) in the SMTP mail header. 
Enter an X-tag to insert into the X-header of mails that match a black list or 
are identified as spam by the anti-spam external database. You can enter up 
to 30 ASCII characters before the colon (:) and up to 47 ASCII characters 
after the colon (:).
You can put any information as an X-tag or use “%status” and/or “%score”.
For example, if you enter “Mail status: %status %score”, you may see “Mail 
status: SPAM 25” in the mail header. That means the mail is classified as 
spam and the spam score is 25.

Phishing Tag

Enter a message or label (up to 16 ASCII characters) to add to the mail 
subject of e-mails that the anti-spam external database classifies as 
phishing.

Note: You must register for and enable the anti-spam external 

database feature in order for the ZyWALL to use this tag 
(see 

 for details).

Spam Tag

Enter a message or label (up to 16 ASCII characters) to add to the mail 
subject of e-mails that the ZyWALL classifies as spam.

Table 88   SECURITY > ANTI-SPAM > General