No Internal Mail Host IP Addresses Found

Products

• Messaging Gateway

Issue/Introduction

Symantec Messaging Gateway (SMG) may begin logging the following error in its logs: "No Internal Mail Host IP Addresses found".

Cause

This error occurs when the list of Internal Mail Host IP Addresses is empty. SMG relies on this list to identify internal MTAs (Mail Transfer Agents) and correctly apply policies.

The relevant setting can be found in the SMG administrative interface:

Administration > Hosts > Configuration > Internal Mail Hosts

If no entries are present in this section, SMG is unable to determine which IP addresses belong to internal mail servers, leading to the above error.

Resolution

To resolve the issue, at least one valid IP address or subnet must be configured under Internal Mail Hosts. The best practice is to re-populate the Internal Mail Hosts section with the default IP address ranges provided by SMG.

0.0.0.0/255.0.0.0
10.0.0.0/255.0.0.0
127.0.0.0/255.0.0.0
169.254.0.0/255.0.0.0
172.16.0.0/255.240.0.0
192.168.0.0/255.255.0.0
::/128
::1/128
fe80::/10
fc00::/7