Do SPF and DKIM records need to be aligned for all email service providers?
Michael Ko
Co-founder & CEO, Suped
Published 7 May 2025
Updated 17 Aug 2025
7 min read
When you're delving into email deliverability, especially with the recent updates from major email service providers (ESPs), questions about SPF and DKIM alignment naturally arise. It's a common area of confusion for many senders, whether you're sending a few thousand emails a week or millions.
The core of the matter revolves around how your domain, as seen in the 'From' header of your emails, is authenticated by the receiving mail servers. SPF and DKIM are the two primary mechanisms for this authentication, but their alignment with your 'From' domain determines their effectiveness in passing DMARC checks. Understanding these nuances is crucial for ensuring your emails consistently reach the inbox.
I often see confusion about whether SPF, DKIM, and DMARC records need to be in perfect alignment with each other, particularly across different email sending platforms. Let's break down the requirements and best practices to clarify this often complex aspect of email authentication.
The prevailing guidance from major mailbox providers, including Google and Yahoo, is that for DMARC to pass, an email only needs to satisfy either SPF alignment or DKIM alignment, not necessarily both. This means if one of these authentication methods aligns with your 'From' domain, your email stands a good chance of passing DMARC and reaching the inbox.
However, while it's not strictly required that both SPF and DKIM align, it is generally considered a strong best practice to configure both for alignment where possible. This dual alignment provides redundancy. If, for instance, there's a transient DNS issue affecting your SPF record, having a properly aligned DKIM signature can act as a fallback, preventing your emails from being flagged or rejected. This can be especially important if you use multiple email services. For deeper insights, you can explore how to implement DMARC, SPF, and DKIM.
Many email service providers will handle the technical aspects of SPF and DKIM for you, but it's important to understand how they implement alignment. Some ESPs might use a shared domain for SPF (the Return-Path or Mail From domain) which may not directly align with your 'From' header domain, resulting in an SPF pass but unaligned SPF. DKIM, however, often offers more control, allowing you to sign emails with your own domain, thereby achieving DKIM alignment.
Managing alignment with multiple email service providers
If you're using multiple ESPs, such as HubSpot, Mailchimp, and SendGrid, the process of ensuring proper authentication becomes a bit more involved. Each ESP needs to be correctly configured to send on behalf of your domain. This typically means setting up DKIM records provided by each individual ESP in your DNS settings. You will likely need multiple DKIM records, one for each service.
For SPF, you'll need a single SPF record that includes all the sending IP addresses or domains authorized by your ESPs. This record lives at your domain's DNS. If you don't combine them correctly, you risk exceeding the 10-lookup limit or invalidating your SPF record altogether, which can lead to deliverability issues. This is why carefully managing your DNS records is critical.
SPF for multiple ESPs
You need one single SPF record that lists all authorized sending sources. If you use multiple ESPs, you must combine their SPF mechanisms into one TXT record to avoid validation failures. For example:
Ensure you don't exceed the 10 DNS lookup limit for SPF records.
Achieving DKIM alignment across multiple services is generally more straightforward than SPF, as each ESP will provide unique DKIM keys (selectors) for your domain. Implementing these DKIM selectors as CNAME records in your DNS is typically all that's required to ensure your emails are signed correctly and align with your 'From' domain.
Strict vs. relaxed alignment for DMARC
DMARC defines two types of alignment: strict and relaxed. Understanding the difference is key to configuring your records effectively. Strict alignment (the 's' tag in DMARC, e.g., adkim=s or aspf=s) means the 'From' header domain must exactly match the SPF 'Return-Path' domain or the DKIM 'd=' tag domain. Relaxed alignment (the 'r' tag) allows for subdomain matches. For example, mail.example.com would align with example.com.
Most email senders opt for relaxed alignment, as it offers greater flexibility, especially when using third-party ESPs that might send from subdomains. Strict alignment can sometimes be too restrictive and cause legitimate emails to fail DMARC checks, even if they pass SPF or DKIM. However, strict alignment does provide an extra layer of security against sophisticated spoofing attempts. It is a trade-off that should be carefully considered based on your sending infrastructure and risk tolerance. You can find DMARC record and policy examples for different scenarios.
Strict alignment
Exact match required: The organizational domain in the 'From' header must precisely match the domain in the SPF 'Return-Path' or DKIM 'd=' tag.
Less flexible: Subdomains will not align with the organizational domain.
Higher security: Offers stronger protection against direct domain spoofing.
Relaxed alignment
Subdomain match allowed: The organizational domain in the 'From' header must match the organizational domain in the SPF 'Return-Path' or DKIM 'd=' tag, allowing for subdomains to pass.
More flexible: Accommodates sending via third-party ESPs that use subdomains.
Wider adoption: Commonly used due to its compatibility with various sending scenarios.
The choice between strict and relaxed alignment impacts how your DMARC policy is enforced. For most organizations, especially those using third-party services, relaxed alignment for both SPF and DKIM is a practical and secure approach that balances deliverability with protection against spoofing.
Why alignment is critical, regardless of volume
With the recent changes from major inbox providers like Google and Yahoo, the emphasis on robust email authentication has never been higher. While the core requirement remains that at least one of SPF or DKIM must align with your 'From' header for DMARC to pass, the expectation is that senders are proactively implementing these standards.
Even if your sending volume is low, neglecting alignment best practices can lead to emails landing in spam folders or being rejected entirely. Inbox providers are increasingly scrutinizing unauthenticated or poorly authenticated mail, regardless of sender volume, to combat phishing and spam.
My advice is to not look for reasons to avoid implementing these crucial authentication methods. Instead, focus on understanding the best practices for setting up SPF, DKIM, and DMARC. Develop a plan, even if you're a smaller sender, to ensure your email infrastructure is fully compliant and optimized for deliverability. This proactive approach will pay dividends in the long run by protecting your sender reputation and ensuring your messages reach their intended recipients.
Views from the trenches
Best practices
Always aim for DKIM alignment first, as it's more robust and survives email forwarding better than SPF.
If using multiple ESPs, ensure your single SPF record includes all authorized sending IP addresses and domains.
Implement DMARC with a relaxed alignment policy (p=none) initially to gather reports and monitor alignment issues before moving to quarantine or reject policies.
Regularly check your DMARC reports to identify any SPF or DKIM alignment failures and address them promptly.
Set up SPF and DKIM authentication for all domains you send from, even transactional email servers not used for marketing.
Common pitfalls
Assuming that passing SPF or DKIM authentication is enough, without considering the crucial aspect of alignment with the 'From' domain.
Creating multiple SPF records, which can invalidate your SPF configuration and lead to authentication failures.
Not configuring DKIM for each individual email service provider, leading to unaligned or failed DKIM signatures.
Ignoring Google and Yahoo's new sender requirements, especially for bulk senders, which now enforce alignment more strictly.
Delaying the implementation of proper email authentication, thinking current low sending volumes exempt them from future requirements.
Expert tips
Even if not strictly required, having both SPF and DKIM aligned provides redundancy and significantly improves email deliverability and trust signals.
Don't wait for your sending volume to hit thresholds before implementing full authentication. Requirements are only getting stricter.
Prioritize DKIM alignment. While SPF is important, DKIM is less prone to breaking during mail forwarding, making it a stronger primary authentication method.
Use DMARC monitoring tools to gain visibility into your email streams and identify sources of unaligned or fraudulent emails.
Be aware of how third-party services (like CRM or invoicing systems) send emails on your behalf and ensure their configuration supports proper alignment.
Marketer view
Marketer from Email Geeks says that their SPF and DKIM appeared to be the generic Mailchimp shared identity, which explained why it was not aligned.
2024-01-11 - Email Geeks
Marketer view
Marketer from Email Geeks says there is no explicit requirement for both SPF and DKIM to align, as Google's guidelines state that only one must align, but having both align is best practice to guard against DNS issues.
2024-01-11 - Email Geeks
The path forward for email authentication
The landscape of email deliverability is constantly evolving, with a clear trend towards stricter authentication requirements. While SPF and DKIM don't always need to be perfectly aligned with each other for DMARC to pass, ensuring that at least one (ideally DKIM) aligns with your 'From' header is paramount.
For serious email senders, regardless of volume, investing the time to correctly configure your SPF, DKIM, and DMARC records across all your sending platforms is non-negotiable. This not only improves your email deliverability but also protects your brand's reputation by preventing unauthorized use of your domain for spam or phishing. Taking these steps now will save you significant headaches and lost opportunities down the line.
HubSpot, 
Mailchimp, and 
SendGrid, the process of ensuring proper authentication becomes a bit more involved. Each ESP needs to be correctly configured to send on behalf of your domain. This typically means setting up DKIM records provided by each individual ESP in your DNS settings. You will likely need multiple DKIM records, one for each service.
