Overview

After changing the lmcfg.txt file to allow TLS by setting $starttls_extension_enabled="true" you notice that message delivery is taking significantly longer than before.

Prerequisites

• To complete the solution you must be running version 12.3.9 or higher. We recommend upgrading to the latest version for optimal performance.
• Access to edit:
  • Windows: C:\Program Files\ListManager\lmcfg.txt
  • Linux: ~/ListManager/bin/lmcfg.txt

Solution

In order to resolve issues related to TLS implementation, it is necessary to implement a new algorithm that balances the connection between the ListManager instance and the destination SMTP server. This solution is especially important when there are a large number of TLS enabled domains on the mailing list. Following this procedure will avoid SMTP server penalties that cause slowness, timeouts, and hard bounces.

1. Navigate to and edit the lmcfg.txt file in order to assign the following values:
   • $starttls_extension_enabled= "true";
   • $logging_of_average_messages_sent_per_connection_enabled = "true";
   • $recipients_ordering_by_domain_first_enabled = "true";
   • $min_messages_per_connection = "10";
2. Save the changes and restart Lyris LM

After the server restarts, message delivery time is improved.

Algorithm Details