Alg Based Email Filtering - D-Link NetDefendOS User Manual

• Source Email Address: *@example.com
• Select OK
6. Select OK
C. Create a custom Service for IMAP:
Web Interface
1. Go to: Objects > Services > Add > TCP/UDP Service
2. Now enter:
• Type: TCP
• Destination: 143
• Protocol: IMAP
3. Click OK
D. Add an IP Policy to allow IMAP traffic and associate the profile with it:
1. Go to: Policies > Firewalling > Add > IP Policy
2. Now enter:
• Name: lan_to_dmz
• Action: Allow
• Source Interface: lan
• Source Network: lan_net
• Destination Interface: dmz
• Destination Network: dmz_net
• Service: my_imap_service
3. Now select Email control and enter:
• Enable Email Control: enable
• Email Control Profile: my_email_profile
4. Select OK

6.4.2. ALG Based Email Filtering

A function of the NetDefendOS SMTP ALG is basic email filtering that provides the ability to filter
mail as it passes to a mail server via the SMTP protocol. Anti-spam filtering can be done based on
the email's origin using external DNS Blacklist servers.
534
Chapter 6: Security Mechanisms