Overview

After some of your internal staff with an @domain.co.uk address send Content to one of your Lists in which they include themselves as recipients, they complain that they do not receive the email form Lyris LM. Instead, the messages are held for members of that domain as 'potential undeliverable'. You suspect that there may be missing DKIM authentication and DNS resolution for internal staff emails @domain.co.uk.

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Prerequisites

• You have set a DNS Server IP Address in Utilities > Administration > Server > Server Settings > Network Settings > DNS and set Use Only for Fallback to Yes.

Use the Lyris LM DNS Diagnostic Tool to determine if the Solution below will solve your issue.

1. From a computer on your network, check what the address that is failing resolves to on the internet using a tool like DNS Checker
   
   
2. Log on to Lyris LM as an Administrator
   
   
3. Navigate to Utilities > Administration > Server > DNS Diagnostic Tool
   
   
   1. Domain Name: Enter the domain name that is not receiving emails, e.g. domain.co.uk
   2. Click Submit

The result from the ListManager internal DNS is displayed unless there is an issue. Compare the result from Step 1 and ListManager. If these two results do not match, proceed to the Solution below.

If ListManager is unable to resolve the domain, verify that port 53 is available to the internet on your network. If ListManager resolves the internal domain incorrectly and everything else correctly, you may need to enter a DNS Bypass for that domain to let ListManager deliver mail to your domain properly. However, when an alternate DNS server is configured in ListManager, try the Solution below first.

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Solution

We strongly recommend using Google DNS (8.8.8.8) for all DNS lookups to ensure rapid delivery of mail. Please follow the steps listed on this article : Lyris LM is Slow After Upgrading to Version 12.x 

However, if you would like to use your own DNS server, you may specify its IP address here.

1. Log on to Lyris LM as an Administrator
   
   
2. Navigate to Utilities > Administration > Server > Server Settings > Network Settings > DNS
   
   
3. Change Use Only for Fallback to No
   
   
4. Click Save

Changing this setting will cause ListManager to use the DNS server IP configured in the DNS Server IP Address field on this page. You can use an internal or external DNS server for this setting.

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Testing

1. From a computer on your network, check what the address that is failing resolves to on the internet using a tool like DNS Checker
   
   
2. Log on to Lyris LM as an Administrator
   
   
3. Navigate to Utilities > Administration > Server > DNS Diagnostic Tool
   
   
   1. Domain Name: Enter the domain name that is not receiving emails, e.g. domain.co.uk
   2. Click Submit

Compare the results from the DNS Checker you used and ListManager's Diagnostic Tool and they match. When internal members send Content to your Lists all internal and external recipients receive the message.