How to resolve SPF alignment issues with Google Workspace alias domains?
Matthew Whittaker
Co-founder & CTO, Suped
Published 16 Jul 2025
Updated 17 Aug 2025
8 min read
Managing email for your business often involves using multiple domains. Google Workspace provides a convenient feature for this: alias domains. An alias domain allows you to send and receive emails from a secondary domain using your primary Google Workspace account. While this functionality is incredibly useful, it introduces a common challenge when it comes to email authentication, specifically with SPF alignment.
The core of the issue lies in how Google Workspace handles the Return-Path (also known as the Mail From or Envelope From) header when you send from an alias domain. Despite the From address showing your alias domain, the Return-Path consistently defaults to your primary Google Workspace domain. This discrepancy means your SPF record will not align with the visible From domain, which can impact email deliverability. I have seen this cause issues with DMARC for a number of years.
Sender Policy Framework (SPF) is a foundational email authentication standard that helps prevent email spoofing. It allows domain owners to publish a DNS TXT record specifying which mail servers are authorized to send email on their behalf. When a receiving server gets an email, it checks the SPF record against the IP address of the sending server. If they match, SPF passes. Alignment takes this a step further, requiring the domain in the Return-Path header to match the From domain for DMARC evaluation. We recently wrote an article that explains why SPF alignment is inconsistent.
With Google Workspace alias domains, the problem isn't that SPF authentication fails, but rather that SPF alignment consistently fails. This is because Google's mail servers will always use the primary domain for the Return-Path header, even when an email is sent from an alias. For instance, if your primary domain is primary.com and your alias is alias.com, an email sent from user@alias.com will have a Return-Path of user@primary.com. This means that the domains for SPF authentication and the From header will not align.
The lack of SPF alignment directly impacts DMARC authentication, which requires at least one of SPF or DKIM to align with the From domain. If SPF alignment consistently fails for alias domains, you become entirely reliant on DKIM to pass DMARC checks. This is why understanding the nuances of how Google Workspace handles these headers is crucial for maintaining good email deliverability and preventing your messages from landing in the spam folder.
The role of DKIM in DMARC alignment
While SPF alignment is a challenge for Google Workspace alias domains, DKIM (DomainKeys Identified Mail) comes to the rescue. DKIM provides a cryptographic signature that verifies the sender's identity and ensures the email hasn't been tampered with in transit. Crucially, Google Workspace is capable of DKIM alignment for alias domains, meaning the domain used in the DKIM signature will match your alias domain.
Key for DMARC pass
Since DMARC only requires one of SPF or DKIM to align to pass, a properly configured DKIM record for your alias domain can ensure your emails pass DMARC checks, even without SPF alignment. This is vital for maintaining good domain reputation and inbox placement. For a full breakdown of these protocols, refer to a simple guide to DMARC, SPF, and DKIM.
To ensure DKIM is correctly set up for your alias domain, you'll need to generate a DKIM key within your Google Workspace Admin console and then add the provided DNS TXT record to your domain's DNS settings. This process is similar to setting up SPF records. You can find detailed instructions on how to set up SPF and DKIM on Google's support pages, ensuring your alias domain is properly authenticated. Keep in mind that DKIM will still align, allowing you to pass DMARC.
Practical steps for improving deliverability
Even though SPF alignment may not be possible for alias domains, implementing a robust DMARC policy is still crucial. A DMARC record tells receiving mail servers how to handle emails that fail authentication checks. Starting with a p=none policy allows you to monitor your email traffic without impacting deliverability, giving you insights into how your alias domains are performing. For further reading, check out our DMARC monitoring solution.
Regularly reviewing your DMARC reports is essential. These reports provide valuable data on which emails are passing or failing SPF and DKIM, and whether they're aligning with your From domain. Even if SPF alignment fails for your alias domain, you should see DKIM passing and aligning. If DMARC reports show overall failures for your alias domain emails, it indicates further investigation is needed beyond just SPF alignment. Learning to understand and troubleshoot DMARC reports from Google and Yahoo is a crucial skill.
Primary domain behavior
SPF alignment: Typically passes, as the Return-Path matches the From domain.
DKIM alignment: Passes if configured correctly for the primary domain.
DMARC status: Should pass, given both SPF and DKIM align.
Alias domain behavior
SPF alignment: Fails, as the Return-Path uses the primary domain.
DKIM alignment: Passes if configured correctly for the alias domain.
DMARC status: Should pass, relying on DKIM alignment.
If you're observing DMARC failures, even with DKIM appearing to be set up correctly, it could be due to other factors. One common pitfall is the presence of multiple SPF records, which can invalidate your authentication. Another is incorrect DNS configuration or issues with mail forwarding services that alter the Return-Path. It's important to troubleshoot SPF and DMARC settings comprehensively to pinpoint the exact cause of any deliverability issues. Additionally, keep an eye on your domain's status on various email blocklists (or blacklists) to ensure your reputation is not being negatively impacted.
Considerations for advanced setups
While alias domains are convenient, if strict SPF alignment for all your sending domains is a non-negotiable requirement, you might consider using secondary domains within Google Workspace. Unlike aliases, secondary domains function as independent domains within your Workspace account and can have their own Return-Path headers that align with their respective From domains, allowing for SPF alignment. However, it's important to note that secondary domains usually incur additional costs, which can be a deciding factor for some organizations.
Email forwarding is another common scenario that can complicate SPF alignment. When an email is forwarded, the Return-Path often changes to that of the forwarding server, causing the original SPF to break alignment. This is a well-known behavior that can impact DMARC authentication, even for primary domains. You may want to review how DMARC policy impacts internal email deliverability when using aliases and forwarding.
SPF record example for Google Workspace
A typical SPF record for a Google Workspace primary domain looks like this. Make sure this is present in your DNS:
TXT recordDNS
v=spf1 include:_spf.google.com ~all
This record authorizes Google's mail servers to send on your behalf. Remember that for alias domains, while this SPF record will pass authentication, it will not align due to the Return-Path behavior.
Even with DKIM alignment for alias domains, continuously monitoring your domain reputation is critical. Tools like Google Postmaster Toolsprovide valuable insights into your email performance, including spam rates, authentication errors, and domain reputation. While SPF misalignment for alias domains is expected, consistent DMARC failures or rising spam rates might indicate other underlying problems, such as content issues or recipient engagement problems. Regularly checking these metrics helps you proactively address potential deliverability hurdles.
Views from the trenches
Best practices
Always ensure DKIM is correctly configured and aligned for your alias domains in Google Workspace, as it is the primary method for DMARC pass.
Regularly monitor your DMARC reports to verify DKIM alignment and identify any email authentication failures.
Understand that SPF alignment for Google Workspace alias domains is typically not achievable by design due to the Return-Path header behavior.
Consider using Google Workspace secondary domains if strict SPF alignment for all sending domains is a critical requirement, despite the potential added cost.
Common pitfalls
Expecting SPF alignment for Google Workspace alias domains, leading to confusion when DMARC reports show unaligned SPF.
Neglecting DKIM setup for alias domains, which can cause DMARC failures and impact deliverability.
Not monitoring DMARC reports, missing critical insights into email authentication performance for both primary and alias domains.
Assuming email forwarding will preserve SPF alignment, which often breaks due to changes in the Return-Path header.
Expert tips
For calendar invites, expect similar SPF non-alignment with alias domains, relying on DKIM for authentication.
Focus on DKIM alignment for alias domains; it's the reliable path to DMARC compliance with Google Workspace.
Secondary domains in Google Workspace offer independent SPF alignment but come with additional licensing costs.
Google's behavior of using the primary domain for the Return-Path is an inherent design of alias domains.
Expert view
Expert from Email Geeks says that SPF alignment for Google Workspace alias domains is an inherent limitation because Google uses the primary domain in the Return-Path.
2024-10-08 - Email Geeks
Expert view
Expert from Email Geeks notes that this behavior is consistent across their experience with Google Workspace.
2024-10-08 - Email Geeks
Key takeaways for SPF and alias domains
The challenge of SPF alignment with Google Workspace alias domains is a common hurdle for many organizations. It boils down to Google's architectural decision to always use the primary domain in the Return-Path header, which prevents SPF alignment with the alias From domain. However, this isn't a dead end for your email deliverability. The key is to leverage DKIM. As Google Workspace is fully capable of DKIM alignment for alias domains, a properly configured DKIM record will ensure your DMARC checks pass, maintaining your email's authenticity.
By understanding this limitation and focusing on robust DKIM implementation, combined with thorough DMARC monitoring, you can effectively manage email deliverability for your Google Workspace alias domains. This approach ensures your emails are authenticated correctly, land in the inbox, and protect your brand's reputation against spoofing and phishing attempts. Always remember that comprehensive email authentication is a layered approach, and relying solely on one mechanism can leave you vulnerable.
Google Workspace provides a convenient feature for this: alias domains. An alias domain allows you to send and receive emails from a secondary domain using your primary Google Workspace account. While this functionality is incredibly useful, it introduces a common challenge when it comes to email authentication, specifically with SPF alignment.
