What problems can redundant email forwarding cause and how to fix it?

Summary

Redundant email forwarding can cause a variety of problems including email loops, deliverability issues, and authentication failures. These issues often stem from misconfigured server settings, circular forwarding rules, forwarding of spam content, or improper MX record configurations. Solutions involve checking and removing unnecessary or redundant forwarding rules, ensuring proper server configuration with correct SPF/DKIM records, implementing loop detection mechanisms, carefully reviewing MTA configuration files, and monitoring email logs for signs of looping. Proper bounce processing is crucial to prevent mail loops caused by forwarded bounce messages. Furthermore, it's essential to trace the origin of loops by analyzing email headers and identifying the servers involved.

Key findings

  • Application Dependency: Redundant forwarding may originate from applications no longer in use; verify dependencies before removal.
  • Authentication Issues: Email forwarding can break authentication depending on its configuration.
  • Bounce Processing: Improper bounce processing can lead to mail loops where bounce messages are forwarded indefinitely.
  • Spam Content: Forwarding spam or undesirable content can damage deliverability.
  • Misconfiguration: Loops often result from misconfigured server settings; inspect forwarding rules.
  • Circular Forwarding: Incorrect server setups can lead to circular forwarding; ensure correct server configuration.
  • Deliverability Issues: Redundant forwarding can cause significant deliverability issues; audit forwarding rules.
  • MTA Misconfiguration: Loops can stem from misconfigured MTAs; review MTA configuration files.
  • Incorrect MX Records: Incorrect MX record configurations combined with forwarding can result in redirection loops.
  • Google Workspace Issues: Incorrect forwarding settings in Google Workspace can lead to email loops.
  • Loop Detection: Implement loop detection to prevent endless email circulation.
  • Relaying Issues: Problems can be introduced in Mail Protocols, so review relaying configurations.
  • Header Analysis: Check email headers to trace the loop's origin and identify involved servers.

Key considerations

  • Configure Authentication: Ensure email forwarding configurations do not interfere with email authentication protocols.
  • Implement Bounce Processing: Set up proper bounce processing to handle bounce messages correctly and prevent them from being forwarded in a loop.
  • Review Forwarding Rules: Regularly check and remove unnecessary email forwarding rules to avoid loops.
  • Ensure Proper Server Configuration: Verify that email servers are correctly configured to handle forwarded emails and have proper SPF and DKIM records.
  • Monitor Email Logs: Continuously monitor email logs for signs of looping to proactively address issues.
  • Trace Loop Origin: Trace where email loops are occurring and resolve multiple forwards to stop problems.
  • Verify MX Records: Ensure that MX records are correctly set up to prevent redirection loops.
  • Check Google Workspace Settings: Review and correct forwarding settings within the Google Workspace admin console.
  • Check Relay Settings: Review the Mail Protocols and check relaying configuration settings.

What email marketers say
10Marketer opinions

Redundant email forwarding can cause email loops, deliverability issues, and authentication problems. These issues typically stem from misconfigured server settings, circular forwarding rules, or forwarding of spam content. Fixing these problems involves checking and removing unnecessary forwarding rules, ensuring proper server configuration, implementing loop detection mechanisms, and monitoring email logs for signs of looping.

Key opinions

  • Application Dependency: Redundant forwarding may originate from applications no longer in use; verify dependencies before removal.
  • Spam Content: Forwarding spam or undesirable content can damage deliverability.
  • Misconfiguration: Loops often result from misconfigured server settings; inspect forwarding rules.
  • Circular Forwarding: Incorrect server setups can lead to circular forwarding; ensure correct server configuration.
  • Deliverability Issues: Redundant forwarding can cause significant deliverability issues; audit forwarding rules.
  • MTA Misconfiguration: Loops can stem from misconfigured MTAs; review MTA configuration files.
  • Loop Detection: Implement loop detection to prevent endless email circulation.
  • Header Analysis: Check email headers to trace the loop's origin and identify involved servers.

Key considerations

  • Review Forwarding Rules: Regularly check and remove unnecessary email forwarding rules to avoid loops.
  • Ensure Proper Server Configuration: Verify that email servers are correctly configured to handle forwarded emails and have proper SPF and DKIM records.
  • Monitor Email Logs: Continuously monitor email logs for signs of looping to proactively address issues.
  • Trace Loop Origin: Trace where email loops are occurring and resolve multiple forwards to stop problems.
Marketer view

Marketer from Email Geeks shares that Forwards can break stuff especially if it's forwarding spam or spam content.

October 2023 - Email Geeks
Marketer view

Email marketer from Reddit suggests that forwarding loops often result from misconfigured server settings. They advise checking the forwarding rules on all associated mailboxes and servers and implementing a loop detection mechanism to prevent emails from endlessly circulating.

April 2022 - Reddit
Marketer view

Email marketer from Reddit says that you should check all the headers and then check who sent the email and if you see more than one, this indicates there is a mail loop problem.

June 2023 - Reddit
Marketer view

Email marketer from EmailGeekBlog explains that you must check your forwards to see if they are still needed. Remove the old forwards and this can fix issues.

April 2023 - EmailGeekBlog
Marketer view

Email marketer from TechHelpNow explains that you need to trace where the loop is occuring, as if you remove one of the forwards involved, there may be another loop present.

July 2021 - TechHelpNow
Marketer view

Email marketer from LinuxQuestions.org explains that loops can stem from misconfigured mail transfer agents (MTAs). They suggest carefully reviewing the MTA configuration files (e.g., Postfix's main.cf) and ensuring that the relay settings do not create circular routes.

May 2021 - LinuxQuestions.org
Marketer view

Email marketer from StackExchange responds that a common cause of email loops is incorrect server setup leading to circular forwarding. They advise to ensure that the destination email server is properly configured to accept forwarded emails and that the sender's domain has the correct SPF and DKIM records.

August 2022 - StackExchange
Marketer view

Email marketer from EmailProviderForum answers that redundant email forwarding can cause significant deliverability issues. They recommend checking all forwarding rules for redundancy and ensuring that each forwarder serves a distinct purpose. Additionally, they advise monitoring email logs for signs of looping.

November 2022 - EmailProviderForum
Marketer view

Marketer from Email Geeks shares that redundant email forwarding is usually from some other application that needs the forward for some reason, although it may no longer be needed. They suggest ensuring that no other application depends on that forward.

November 2021 - Email Geeks
Marketer view

Email marketer from Quora says that to avoid email looping, make sure the mail server isn't forwarding to itself. Remove the forwarding.

May 2022 - Quora

What the experts say
2Expert opinions

Redundant email forwarding can cause issues with authentication, and proper bounce processing is crucial to prevent mail loops. When an email is forwarded and bounces, that bounce message can create a forwarding loop.

Key opinions

  • Authentication Issues: Email forwarding can break authentication depending on its configuration.
  • Bounce Processing: Improper bounce processing can lead to mail loops where bounce messages are forwarded indefinitely.

Key considerations

  • Configure Authentication: Ensure email forwarding configurations do not interfere with email authentication protocols.
  • Implement Bounce Processing: Set up proper bounce processing to handle bounce messages correctly and prevent them from being forwarded in a loop.
Expert view

Expert from Word to the Wise, Laura Atkins, emphasizes the importance of setting up proper bounce processing to prevent mail loops. She explains that when an email is forwarded and bounces, the bounce message can be forwarded as well, creating a loop. Proper bounce processing ensures that these bounces are handled correctly, preventing them from being forwarded indefinitely. This involves configuring your mail server to recognize and handle bounce messages appropriately, avoiding any forwarding of these notifications.

February 2024 - Word to the Wise
Expert view

Expert from Email Geeks explains that Authentication can break depending on how the forwarding is configured.

January 2024 - Email Geeks

What the documentation says
5Technical articles

Redundant email forwarding can lead to email loops due to misconfigured mail server settings, improper MX records, and incorrect forwarding rules. Solutions include identifying misconfigured servers, correcting forwarding rules to prevent circular routing, verifying MX records, and reviewing relay settings.

Key findings

  • Mail Server Misconfiguration: Email loops occur due to repeated message forwarding caused by misconfigured mail server settings.
  • Circular Forwarding Paths: Improper forwarding setups create circular paths, leading to email loops.
  • Incorrect MX Records: Incorrect MX record configurations combined with forwarding can result in redirection loops.
  • Google Workspace Issues: Incorrect forwarding settings in Google Workspace can lead to email loops.
  • Relaying Issues: Problems can be introduced in Mail Protocols, so review relaying configurations.

Key considerations

  • Identify Misconfigured Servers: Locate the specific mail server causing the loop and correct the configuration.
  • Review Forwarding Rules: Carefully check and adjust forwarding rules to prevent circular paths.
  • Verify MX Records: Ensure that MX records are correctly set up to prevent redirection loops.
  • Check Google Workspace Settings: Review and correct forwarding settings within the Google Workspace admin console.
  • Check Relay Settings: Review the Mail Protocols and check relaying configuration settings.
Technical article

Documentation from Microsoft Learn explains that email loops occur when mail server configurations cause messages to be repeatedly forwarded. This can overload the system and prevent delivery. Solutions include identifying the misconfigured server and correcting the forwarding rules to prevent self-referencing or circular routing.

October 2021 - Microsoft Learn
Technical article

Documentation from cPanel highlights that improper forwarding setups can cause email loops. The documentation advises to carefully review all forwarders to ensure they do not create circular paths (e.g., email@domain1.com forwards to email@domain2.com, which then forwards back to email@domain1.com). Use cPanel's email trace feature to diagnose forwarding issues.

November 2023 - cPanel
Technical article

Documentation from MDN Web Docs explains that incorrect MX record configurations combined with forwarding can lead to loops. The guide recommends verifying MX records and ensuring that the forwarding rules do not conflict with the server's DNS settings, which can lead to redirection loops.

September 2024 - MDN Web Docs
Technical article

Documentation from RFC Editor shares that to avoid email looping problems you should review the Mail Protocols and look for where problems can be introduced. The summary suggests also checking relaying configuration.

July 2021 - RFC Editor
Technical article

Documentation from Google Workspace Admin Help notes that incorrect forwarding settings in Google Workspace can lead to email loops. They recommend reviewing forwarding rules in the admin console and ensuring that no rules forward emails back to the original address or to another address that then forwards back.

March 2024 - Google Workspace Admin Help