Answer
PROBLEM
GFI MailEssentials is processing emails very slowly. This causes eventually a queue of emails to be built up, especially in installations with large email flow. When GFI MailEssentials is installed on Microsoft Exchange server, emails appear to stop in the Microsoft Exchange pre-submission queue.
ENVIRONMENT
- GFI MailEssentials
- all supported environments
SOLUTION
In GFI MailEssentials the anti-spam settings / DNS server settings page has a ‘Test’ button. The ‘Test’ button should be used to verify the connection to the DNS server.
If the ‘Test’ returns a failure, this will indicate issues with the connection to the DNS server. Hence any DNS checks should be disabled temporarily from within GFI MailEssentials, until all DNS related issues are resolved.
If the ‘Test’ returns a failure, this will indicate issues with the connection to the DNS server. Hence any DNS checks should be disabled temporarily from within GFI MailEssentials, until all DNS related issues are resolved.
The following section is a summary of advises how to troubleshoot DNS issues:
-
Use nslookup as follows to ensure that the default DNS server is correct
- Open a command prompt
- Type nslookup and press Enter
- Type a domain that you would like to query (for example: gfi.com), and ensure that there are no delays in the result
- Check the Microsoft event viewer to see whether the Microsoft event logs contain any DNS related errors
- Check the Directory Service logs on the GFI MailEssentials machine and the DNS logs on the DNS server
- Use a command prompt to launch the DC Diagnosis tool by typing dcdiag /v to diagnose any errors
CAUSE
This issue may be seen when DNS problems occur in the network and one of the following options are enabled:
- IP DNS Blocklists (GFI MailEssentials configuration > Anti-Spam > Anti-Spam Filters > IP DNS Blocklists)
- Sender Policy Framework (GFI MailEssentials configuration > Anti-Spam > Anti-Spam Filters >Sender Policy Framework)
- URI DNS Blocklist (GFI MailEssentials configuration > Anti-Spam > Anti-Spam Filters > URI DNS Blocklist)