How can I change the retransmission time in Postfix?

Summary

To change the retransmission time in Postfix, you need to modify the `main.cf` configuration file. The most relevant parameters are `transport_retry_time`, `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay`. `transport_retry_time` sets the time between attempts to a malfunctioning transport. The backoff times dictate the range of retry delays. Decreasing `queue_run_delay` makes Postfix retry more frequently, but can increase system load. If facing greylisting issues, consider whitelisting instead of solely adjusting Postfix settings. Understanding how these parameters interact is crucial for optimizing delivery. Be sure to test changes to avoid overloading the server. `delay_warning_time` affects delivery notifications, not retransmission itself.

Key findings

  • main.cf Parameters: Configuration is primarily done through parameters in the `main.cf` file.
  • transport_retry_time: Sets the time between attempts to a malfunctioning transport.
  • Backoff and Queue Parameters: `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` are key for retry configuration.
  • Greylisting Alternative: For greylisting, whitelisting is a potential alternative to adjusting retry times.

Key considerations

  • System Load: Reducing `queue_run_delay` can increase system load; test thoroughly.
  • Parameter Interaction: Understanding the interplay of parameters is critical for effective tuning.
  • Greylisting Handling: Address greylisting issues through appropriate methods, such as whitelisting.
  • delay_warning_time: `delay_warning_time` influences notifications, not retry frequency.

What email marketers say
10Marketer opinions

To modify the retransmission time in Postfix, you primarily need to edit the `main.cf` configuration file. Several parameters influence retry behavior, including `transport_retry_time`, `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay`. Adjusting these parameters allows you to control how often Postfix attempts to resend emails and the range of the retry intervals. Be mindful of greylisting and server load when making changes.

Key opinions

  • main.cf Configuration: The primary configuration file for adjusting retransmission settings is `main.cf`.
  • Retry Parameters: Key parameters to modify include `transport_retry_time`, `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay`.
  • Backoff Times: `minimal_backoff_time` and `maximal_backoff_time` control the range of delays for retries.
  • Queue Run Delay: Decreasing `queue_run_delay` causes Postfix to retry more frequently.

Key considerations

  • Greylisting: If dealing with greylisting, consider whitelisting or integrating with a greylisting daemon instead of solely adjusting Postfix.
  • Server Load: Always test changes to ensure you do not overload the server.
  • Parameter Impact: Understand the impact of each parameter to fine-tune Postfix's retry behavior effectively.
Marketer view

Email marketer from ServerFault answers that you can tune Postfix retry settings by adjusting `minimal_backoff_time` (default: 100s), `maximal_backoff_time` (default: 4000s), and `queue_run_delay` (default: 300s). He suggests experimenting with these values based on your specific needs, such as reducing the delay for local network issues.

June 2024 - ServerFault
Marketer view

Marketer from Email Geeks shares that you can set the retransmission time in Postfix by modifying the `transport_retry_time` setting in the `main.cf` file. The default time unit is seconds, but can be set in seconds (s), minutes (m), hours (h), days (d), weeks (w).

May 2023 - Email Geeks
Marketer view

Email marketer from DigitalOcean explains that to modify the retry intervals, you need to edit the `main.cf` file, typically located in `/etc/postfix`. You can adjust parameters like `minimal_backoff_time` and `maximal_backoff_time` to influence how frequently Postfix retries sending emails.

October 2023 - DigitalOcean
Marketer view

Email marketer from Reddit explains that the parameters `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` control Postfix's retry behavior. The backoff times determine the range of time to wait between retries, and the queue run delay specifies how often Postfix scans the queue for deferred messages.

August 2022 - Reddit
Marketer view

Email marketer from Super User shares that you can adjust parameters such as `queue_run_delay`, `minimal_backoff_time`, and `maximal_backoff_time`. By configuring these, you can influence how often Postfix attempts to resend the email and the range of the retry intervals.

October 2024 - Super User
Marketer view

Email marketer from OpenStack documentation shares that in the context of OpenStack, if you are experiencing delays in email delivery, you can adjust Postfix's `queue_run_delay` parameter in the `/etc/postfix/main.cf` file to control how frequently the queue is processed.

March 2022 - OpenStack
Marketer view

Email marketer from LinuxQuestions.org explains you can change the retry time by setting `queue_run_delay`, `minimal_backoff_time` and `maximal_backoff_time` in main.cf. Decreasing `queue_run_delay` makes Postfix retry more often. The backoff times control the range of delays for retries.

January 2024 - LinuxQuestions.org
Marketer view

Email marketer from Stack Overflow explains that you can modify the `minimal_backoff_time` and `maximal_backoff_time` parameters in Postfix's main.cf file to control the retry interval for deferred messages. These settings define the initial and maximum delay Postfix will use when retrying delivery.

February 2022 - Stack Overflow
Marketer view

Email marketer from Plesk forum explains that the default settings for retry intervals in Postfix are often sufficient, but if you need faster retries, you might consider lowering the `queue_run_delay` and `minimal_backoff_time` parameters. Always test your changes to ensure you do not overload the server.

August 2024 - Plesk
Marketer view

Email marketer from Unix & Linux Stack Exchange suggests if the goal is to immediately retry after greylisting, adjusting Postfix alone might not be sufficient. Instead, explore methods for handling greylisting more gracefully such as whitelisting or integrating with a greylisting daemon to manage retry attempts.

November 2024 - Unix & Linux Stack Exchange

What the experts say
1Expert opinion

Tuning Postfix involves understanding how parameters like `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` interact to optimize email delivery.

Key opinions

  • Parameter Understanding: A key finding is the importance of understanding the effect of the parameters.
  • Parameter Interaction: The parameters need to be understood how they work together.

Key considerations

  • Optimizing Delivery: Understanding parameter relationships is key to optimizing delivery.
Expert view

Expert from Word to the Wise explains that when tuning Postfix, it is important to understand the effect of parameters such as `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay`. Understanding how these work together is key to optimizing delivery.

November 2021 - Word to the Wise

What the documentation says
4Technical articles

Postfix documentation outlines several parameters that control retransmission behavior. `transport_retry_time` sets the interval between attempts to contact a malfunctioning transport. `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` should be configured within the `main.cf` file to adjust retry intervals. Lowering `queue_run_delay` increases retry frequency but can increase system load. `delay_warning_time` is related to delivery status notifications, not retry settings.

Key findings

  • transport_retry_time: Specifies the time between attempts to contact a malfunctioning transport; default is 60s.
  • Retry Parameters: `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` control retry intervals.
  • queue_run_delay: Defines the time between deferred queue scans; lowering it increases retry frequency.
  • Configuration File: Parameters are configured in the `main.cf` file.

Key considerations

  • System Load: Lowering `queue_run_delay` increases system load.
  • delay_warning_time: `delay_warning_time` is for notifications, not retry configuration.
Technical article

Documentation from Postfix.org explains that the `transport_retry_time` parameter specifies the time between attempts by the Postfix queue manager to contact a malfunctioning message delivery transport. Time units can be specified in seconds (s), minutes (m), hours (h), days (d), or weeks (w). The default is 60s.

April 2024 - Postfix.org
Technical article

Documentation from Postfix.org details that the parameter `delay_warning_time` determines when Postfix will send a warning message to the sender about a delayed email. This is not a retry setting, but it is related to the email's delivery status and can be helpful for monitoring delivery issues.

September 2024 - Postfix.org
Technical article

Documentation from Postfix.org explains that `queue_run_delay` specifies the time between deferred queue scans. Lowering this value will cause Postfix to retry failed deliveries more frequently, but may increase system load.

April 2024 - Postfix.org
Technical article

Documentation from Postfix.org details that to adjust the time Postfix waits before retrying a failed delivery, you should configure the `minimal_backoff_time`, `maximal_backoff_time`, and `queue_run_delay` parameters within the `main.cf` configuration file.

February 2024 - Postfix.org