IMSS blocks
all messages if they do not originate from the trusted internal
IP address list. This filter triggers only on messages where the
sender’s and recipient’s domains are the same.
Procedure
- Under Others on the scanning conditions selection screen, select the check box next to Spoofed internal messages.
- Click Spoofed internal messages. The Spoofed Internal Messages screen appears.
WARNING
All edge MTA IP addresses must be added to this list if the feature is enabled. If the IP addresses are not added to the list, all messages from the edge MTAs that are not added will be blocked. - Add IP addresses to the Trusted Internal IP List.
- Click Save.