How do Google Groups impact DMARC when forwarding emails from multiple domains?
Summary
What email marketers say8Marketer opinions
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.
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.
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.
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.
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.
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.
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.
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.
What the experts say6Expert opinions
Expert from Email Geeks explains that when you forward an email, the sender's authentication settings matter, not the original sender's.
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.
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.
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.
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.
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.
What the documentation says5Technical articles
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.
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.
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.
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.
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.