This article applies to:
- Trustwave MailMarshal (SEG)
Symptoms:
Event ID: 2508
Type: Warning
Source: MMReceiver
Description: DNS alert raised
The configured DNS server is not responding to queries from the MailMarshal SMTP Receiver service.
Causes:
This event is raised whenever the MailMarshal Receiver service encounters a number of successive failures querying DNS (by default, 3).
The MailMarshal Receiver uses DNS for DNS Blocklist queries and other verification purposes.
This issue is typically due to slow or unresponsive DNS servers, or basic network connectivity issues between MailMarshal and the host configured as MailMarshal's DNS server.
- In recent versions of SEG the Controller service performs DNS lookups and maintains a cache.
More Info:
MailMarshal uses the DNS servers configured in its "Delivery" settings for all DNS-related queries. These may not be the same DNS servers configured on the computer's network interface.
For more information, see Q10050: DNS alerts appear in the MailMarshal Console.
