F-Secure Internet Gatekeeper for Linux/Administrator’s Guide
105
10.1.5
Authentication using POP-before-SMTP
Internet
Mail server
SMTP access
prohibited
SMTP
Access
granted
POP
authentication
successful
POP
authenticati
on fails
User A
User B
Anti-Virus Gateway
SMTP services can be accessed using POP-before-SMTP. If POP-before-SMTP is used, user
authentication for a POP connection is performed before a SMTP service is accessed. Access to the
SMTP service is limited to IP addresses that have passed POP authentication within a specified time.
In addition, POP-before-SMTP authentication is performed in F-Secure Internet Gatekeeper for Linux.
This is because the IP address of the product is always assigned to the IP address of the sender’s
mail server.
To use POP-before-SMTP authentication, configure the SMTP and POP services in the following way.
Proxy Settings
Proxy settings
SMTP proxy:
On
Global settings
POP-before-SMTP authentication:
On
Timeout: Specify the time in minutes during which the authentication is effective
(Example:
2)
POP proxy:
On
The following settings allow services without authentication to clients within the LAN and to senders
from specific mail servers, addresses and networks:
Proxy settings
SMTP proxy
LAN access settings:
On
Hosts and networks within LAN:
Specify allowed clients
(Clients within the LAN, mail servers, etc.)