How do Google Groups impact DMARC when forwarding emails from multiple domains?

Summary

Forwarding emails through Google Groups introduces a multitude of challenges for DMARC compliance. The primary issues stem from alterations to the email's original authentication data. When an email is forwarded, the SPF record often becomes invalid because the email is now being sent from a different server, not authorized by the original sending domain. Furthermore, Google Groups may modify email headers or the body (e.g., adding a footer), invalidating DKIM signatures. Consequently, since DMARC relies on both SPF and DKIM passing and aligning with the From: domain, these alterations commonly result in DMARC failures. Using simplified email aliases or routing rules could be a more suitable workaround in specific scenarios. Properly setting up, and then regularly reviewing DMARC compliance, is recommended, or your messages may be marked as spam or rejected.

Key findings

  • SPF Invalidation: Forwarding changes the sending server, invalidating the original SPF record.
  • DKIM Breakage: Message modifications during forwarding break DKIM signatures.
  • Unauthorized Forwarding: Forwarding servers may not be authorized to send on behalf of the original domain.
  • DMARC Dependence: DMARC relies on SPF and DKIM, so failures in either cause DMARC to fail.
  • Alias domain SPF usage: Google Workspace always uses the main domain in the SPF/return path for alias domains, complicating SPF alignment.

Key considerations

  • Alternative Solutions: Consider using simple email aliases or routing rules instead of Google Groups to avoid DMARC issues.
  • Group Configuration: Avoid configuring Google Groups to modify message bodies or footers to preserve DKIM signatures.
  • SPF Records: Assess if the forwarding servers used by Google Groups can be included in the SPF record of the sending domain (though often not feasible).
  • DMARC Monitoring: Monitor DMARC reports to identify forwarding issues and take appropriate action.
  • Impact Assessment: Understand the impact of DMARC policies on forwarded emails and consider appropriate actions (e.g., monitoring, quarantining).
  • Authentication practices: Review your domain SPF, DKIM, and DMARC authentication practices regularly to maintain deliverability.

What email marketers say
8Marketer opinions

Forwarding emails through Google Groups can lead to DMARC failures due to several reasons. Google Groups may modify email headers or content, invalidating DKIM signatures. The forwarding server used by Google Groups is often not included in the original sender's SPF record, causing SPF alignment to fail. This lack of SPF/DKIM alignment with the original sending domain results in DMARC failing and potentially leading to email rejection or quarantine.

Key opinions

  • Header/Content Modification: Google Groups may alter email headers or content during forwarding, invalidating DKIM signatures.
  • SPF Alignment Failure: The forwarding server used by Google Groups is typically not included in the original sender's SPF record, causing SPF alignment to fail.
  • DMARC Failure: The combination of SPF and DKIM failures leads to DMARC failure, which can result in email rejection or quarantine.
  • Unauthorized Forwarding: The forwarding action is not authorized on behalf of the original sending domain.

Key considerations

  • DMARC Configuration: Ensure DMARC is configured correctly for all sending domains to protect against spoofing.
  • Forwarding Authorization: Consider implementing mechanisms to authorize Google Groups to forward emails on behalf of the original domain (though this may be complex or impractical).
  • Alternative Solutions: Evaluate alternative solutions to Google Groups that are more DMARC-friendly.
  • Impact Assessment: Assess the impact of DMARC policies (p=quarantine/reject) on legitimate forwarding scenarios and adjust accordingly.
Marketer view

Email marketer from LinkedIn explains that forwarding through services like Google Groups can invalidate DMARC because the SPF and DKIM records of the original sender don't match the forwarding server. This is a common problem with automated forwarding systems that aren't designed to handle DMARC properly.

March 2022 - LinkedIn
Marketer view

Email marketer from EmailAuth shares that forwarding through Google Groups often leads to DMARC failures because the original sender's SPF and DKIM records don't align with the forwarding server. The forwarding process can modify the email, invalidating DKIM, and the forwarder isn't authorized in the SPF record.

March 2021 - EmailAuth
Marketer view

Email marketer from EasyDMARC explains that when emails are forwarded via Google Groups, the SPF record checks may fail if the forwarding server isn't included in the sender's SPF record. Additionally, if the message content is altered during forwarding (e.g., by adding a disclaimer), DKIM validation will fail. Both of these failures lead to a DMARC failure.

October 2023 - EasyDMARC
Marketer view

Email marketer from MXToolbox states that forwarding through Google Groups can disrupt DMARC compliance. The SPF record might not include the Google Groups server, and DKIM signatures can be invalidated if the email is altered during forwarding.

March 2022 - MXToolbox
Marketer view

Email marketer from Reddit explains that Google Groups forwarding often causes DMARC failures because the group acts as an intermediary sender. The original SPF record doesn't include the Google Groups server, and any alterations to the email invalidate the DKIM signature.

October 2021 - Reddit
Marketer view

Email marketer from Dmarcian shares that DMARC failures often occur with forwarding because the forwarder is not authorized to send on behalf of the original domain. Google Groups, acting as a forwarder, can cause these failures if not properly configured to handle DMARC.

December 2023 - Dmarcian
Marketer view

Email marketer from Mailhardener explains that Google Groups may alter the message headers or body, which can invalidate existing DKIM signatures. If the message is forwarded from a domain different from the original sender's domain, SPF alignment will also likely fail, leading to DMARC failure.

October 2023 - Mailhardener
Marketer view

Email marketer from StackOverflow mentions that mailing lists, similar to Google Groups, can interfere with DMARC validation because the forwarding server may not be authorized by the sending domain. This causes SPF and/or DKIM checks to fail, leading to DMARC rejection or quarantine.

January 2025 - StackOverflow

What the experts say
6Expert opinions

Forwarding emails through Google Groups introduces DMARC compliance challenges because the original SPF and DKIM records may not align with the forwarding server. The forwarding process can alter email headers and content, invalidating DKIM signatures. Google Workspace uses the main domain's SPF for alias domains, complicating SPF alignment. Because forwarding changes the email path, potentially using different servers, DMARC validation can fail. A better solution may be to use simple email aliases rather than Google Groups.

Key opinions

  • SPF Alignment Issues: Google Workspace uses the main domain's SPF, making it difficult to align SPF for alias domains when forwarding.
  • DKIM Invalidation: Forwarding can alter email headers and content, invalidating DKIM signatures.
  • Server Mismatch: Forwarding uses a different server than the original sender, causing SPF alignment to fail.
  • Impact on DMARC: These issues lead to DMARC failures, potentially resulting in email rejection or quarantine.
  • Sender Authentication Matters: When forwarding, the sender's authentication settings matter, not the original sender's settings.

Key considerations

  • Alternative Solutions: Consider using simple email aliases or routing rules instead of Google Groups to avoid DMARC issues.
  • Domain Strategy: Re-evaluate your domain strategy within Google Workspace, considering the implications of alias domains.
  • Impact Assessment: Carefully assess how forwarding affects your DMARC compliance and implement appropriate mitigation strategies.
  • Header Examination: Examine full email headers to understand the exact changes introduced during the forwarding process.
Expert view

Expert from Email Geeks explains that when you forward an email, the sender's authentication settings matter, not the original sender's.

November 2022 - Email Geeks
Expert view

Expert from Email Geeks explains that updating the SPF for the short domain won't solve the alignment issue that is causing the DMARC failure when forwarding from a google group.

November 2023 - Email Geeks
Expert view

Expert from Email Geeks explains that Google Workspace mail always uses the main domain in the SPF/return path when using a user alias domain. Therefore, adding the shortened domain to the primary domain's SPF will not solve the alignment issue. He also mentions he is planning to blog about the lack of SPF alignment on alias domains in Google Workspace.

November 2021 - Email Geeks
Expert view

Expert from Email Geeks suggests that Google Groups may not be suitable for all scenarios and that "dumb" email aliases might be a better solution. He shares an example of replacing a Google Group with a routing rule in Gmail admin settings to avoid issues with header rewriting and accidental unsubscribes.

November 2022 - Email Geeks
Expert view

Expert from SpamResource explains that forwarding can cause DMARC failures, and Google Groups are no exception. Because the email is being sent from a different server than originally intended, and because the headers may be altered in the process, DMARC validation can fail.

October 2023 - SpamResource
Expert view

Expert from Word to the Wise explains that a major cause of DMARC failures is mailing lists and forwarding. Any change in the path from sender to recipient can break DMARC, and Google Groups can do exactly that.

June 2021 - Word to the Wise

What the documentation says
5Technical articles

Forwarding emails through Google Groups often leads to DMARC failures. This is primarily due to SPF and DKIM authentication issues. SPF authenticates the sender, but when an email is forwarded, the originating server changes, invalidating the initial SPF record. This happens because the intermediate server (Google Groups) might not be authorized to send on behalf of the original domain. Additionally, if Google Groups modifies the message content (e.g., adding a footer), DKIM signatures are broken. DMARC relies on both SPF and DKIM, so when either fails, the DMARC check fails as well, potentially resulting in emails being marked as spam or rejected.

Key findings

  • SPF Invalidation: Forwarding changes the sending server, invalidating the original SPF record.
  • DKIM Breakage: Message modifications during forwarding break DKIM signatures.
  • Unauthorized Forwarding: Forwarding servers may not be authorized to send on behalf of the original domain.
  • DMARC Dependence: DMARC relies on SPF and DKIM, so failures in either cause DMARC to fail.

Key considerations

  • Group Configuration: Avoid configuring Google Groups to modify message bodies or footers to preserve DKIM signatures.
  • SPF Records: Assess if the forwarding servers used by Google Groups can be included in the SPF record of the sending domain (though often not feasible).
  • Alternative Methods: Consider using alternative methods for group communication that are more compatible with DMARC.
  • DMARC Policies: Understand the impact of DMARC policies on forwarded emails and consider appropriate actions (e.g., monitoring, quarantining).
Technical article

Documentation from RFC 7489 (DMARC standard) explains that forwarding can break DMARC authentication because the intermediate server (like Google Groups) might not be authorized to use the original sender's domain. The forwarded email's SPF record will likely fail to align, and DKIM signatures may become invalid due to header modifications during forwarding.

January 2023 - RFC Editor
Technical article

Documentation from AuthSMTP explains that SPF (Sender Policy Framework) authenticates the sender of an email. When an email is forwarded, the SPF record may no longer be valid because the email is now being sent from a different server. This can cause SPF checks to fail, which causes DMARC failures.

April 2024 - AuthSMTP
Technical article

Documentation from Google Workspace Admin Guide explains that when a message is sent to a Google Group, and then forwarded by the group, DMARC can fail if the forwarding modifies the message in a way that breaks DKIM signatures or alters SPF alignment. This is especially true if the group is configured to add a footer or modify the message body.

July 2024 - Google Workspace Admin Guide
Technical article

Documentation from Microsoft explains that SPF authenticates the sender of an email, but when an email is forwarded, the original SPF record may no longer be valid because the email is now being sent from a different server. This can cause SPF checks to fail, leading to DMARC issues if the forwarding server is not authorized.

March 2022 - Microsoft
Technical article

Documentation from Validity's ReturnPath explains that common reasons for DMARC failure include forwarded emails and mailing lists. When an email is forwarded through Google Groups, it is re-sent through a different server than the originating source, potentially causing SPF and DKIM to fail.

November 2022 - Validity