Why Your SPF Record Breaks When Using Multiple ESPs

You send transactional emails through SendGrid,营销 emails through Mailchimp, and automation via Klaviyo. Your inbox placement drops. Bounces spike. You check the logs, and the reason? SPF validation failed.

SPF records are like a domain’s ID badge for email servers. But they only work if the badge is correct, complete, and not overcrowded. When you use multiple ESPs, you’re forced to merge their requirements into one record—but most people don’t know how. And that’s why your SPF breaks.

You’re not alone. A common mistake is assuming each ESP can have its own SPF record. They can’t. Only one SPF record is allowed per domain. When you pile multiple include mechanisms without oversight, you quickly hit the 10 DNS lookup limit or trigger invalid syntax—both of which break authentication.

That’s the core issue: your SPF record for multiple ESPs example won’t work unless you merge them correctly. Misconfigured SPF causes emails to be rejected, flagged as spam, or silently dropped. Inbox placement plummets. Reputation takes a hit. The fix? A single, well-constructed SPF record.

Key takeaways

  • Only one SPF record is allowed per domain, even when using multiple ESPs.
  • Exceeding 10 DNS lookups in an SPF record triggers validation failure.
  • Using multiple include mechanisms without merging them leads to SPF authentication failure.

What Does 'SPF Record for Multiple ESPs Example' Mean in Practice?

You’re using more than one email service provider—say, SendGrid for transactional emails and Mailchimp for marketing—so you need a single SPF record that includes both. When you send from your domain, the receiving server checks the SPF record. If it doesn’t recognize your ESP as authorized, the email may bounce or land in spam. A properly configured SPF record for multiple ESPs ensures both services pass the check, maintaining deliverability and sender reputation.

How SPF Works with Multiple Providers

Each ESP you use adds a mechanism to your SPF record—like include:sendgrid.net and include:mailchimp.com. You combine these into one record, limited to a maximum of 10 DNS lookups. Exceeding that breaks SPF validation, so you must keep it lean. If one provider is no longer used, remove its include to avoid hitting the limit.

SPF records are checked during email delivery, and a failed check can trigger rejection. For example, if you send via SendGrid but your SPF record only includes Mailchimp, the recipient server sees this as unauthorized. The email may bounce, or worse, be marked as spam. This damages sender reputation over time, reducing inbox placement.

Use a tool like MailTester’s bulk verification to test whether your domain’s SPF setup allows all your senders to pass. It also checks for common misconfigurations, including overlong records and invalid includes.

Best Practices for SPF Records with Multiple ESPs

Always include only the ESPs you actually use. Over-including adds unnecessary DNS lookups and risks failure. Test your setup using an SPF validator like the one at MxToolbox or RFC 7208, which defines SPF syntax and limits.

Consider using DMARC with SPF. DMARC lets you monitor and enforce authentication policies. It doesn’t prevent SPF failure, but it helps detect when issues arise and gives you data to fix them early.

For real-time validation, integrate with the MailTester API to verify senders on the fly. This helps catch SPF-related problems before they affect your mailing list.

SPF Multiple Includes: The Technical Reality You Must Know

You can have multiple ESPs in your SPF record, but each include mechanism counts as a DNS lookup. SPF validation stops after 10 lookups — going over that causes SPF failure even if your record looks correct. This limit applies regardless of how you structure your includes, so oversimplifying your setup can break authentication.

Why 10 Lookups Is a Hard Limit

SPF record validation is defined by RFC 7208, which explicitly caps the number of DNS lookups at 10 per validation. Every time your SPF record includes another domain — like include:_spf.sendgrid.net or include:spf.mandrillapp.com — it triggers a separate DNS query.

If you're using 10+ ESPs, each with their own include, you're already at the limit. Even one extra include pushes you over, and your email fails SPF checks. This isn’t a configuration error — it’s a built-in restriction in the SPF specification.

Practical Implications for Multi-ESPs

Let’s say you use SendGrid, Mailgun, and Amazon SES, plus internal systems. That’s three includes right off the bat. If your ESPs each reference other SPF records (a common practice), you can easily hit the 10-lookup ceiling without meaning to.

When SPF fails, your messages may be rejected, marked as spam, or delayed. Even if your DNS record is syntactically correct, exceeding the limit means it's rejected by receiving servers. This isn’t theoretical — it's how SPF is implemented across the internet.

If you use multiple ESPs, your best bet is to consolidate where possible or use a single, trusted email service with delegated capabilities (like MailTester’s integrations with SendGrid, HubSpot, or Klaviyo).

Want to validate your SPF setup before sending? Try inbox placement testing with real inboxes via MailTester’s Inbox Tester. It checks not just SPF, but also DKIM, DMARC, and deliverability risk across major providers.

For bulk verification of your list — especially if you're managing sender reputation across multiple ESPs — use MailTester’s bulk verification. It checks for invalid, catch-all, and risky addresses, helping you maintain high deliverability. The verification API makes this scalable for automated workflows.

Step-by-Step: How to Combine SPF for Two Providers (with Example)

You can combine SPF records for multiple ESPs by merging all include mechanisms into one record, using only include and ip4 directives, and ensuring no more than one SPF record exists per domain. For example, if you use SendGrid and Mailchimp, your SPF should list both providers' include tags—like include:sendgrid.net include:mailchimp.com—and avoid duplicate or conflicting entries. Always test the result after deployment.

Check Your Existing SPF Record

Start by checking your current SPF configuration using a public tool like MxToolbox or your DNS provider’s lookup service. This shows the exact text of your current record. If you see multiple SPF records, you’ll need to consolidate them—only one SPF record per domain is allowed, per email standards (RFC 7208).

Identify and Confirm Your ESPs’ SPF Requirements

List all email service providers you send through—common ones include SendGrid, Mailchimp, Klaviyo, HubSpot, and others. Confirm each offers a public, documented SPF mechanism. Most do; they publish their SPF syntax in developer documentation or support guides. If an ESP doesn’t provide an SPF include, you may need to use their IP addresses directly via ip4 (recommended only when needed).

  1. Collect all include mechanisms from each ESP’s documentation. For example: include:sendgrid.net and include:mailchimp.com.
  2. Build a single SPF record using only include and ip4 mechanisms. Avoid all unless absolutely necessary—using ~all or -all can harm deliverability if misconfigured.
  3. Limit the record to one entry. Combine all includes into a single SPF TXT record. Example: v=spf1 include:sendgrid.net include:mailchimp.com ~all.
  4. Do not include multiple SPF records. Multiple records trigger SPF failures. If your DNS already has a TXT record with SPF, merge any other SPF-related entries into that one.
  5. Test the result by sending from each ESP and verifying the outcome using a tool like MailTester’s Inbox Tester. This checks whether the email passes SPF and reaches the inbox.

Some email platforms, like Mailchimp or SendGrid, have known SPF quirks—especially around subdomains or shared IPs—so always verify the final setup. Using MailTester’s bulk verification can help identify issues across your list before deployment.

SPF is strict about syntax. A single typo can cause full message rejection. Always validate via an authoritative source like RFC 7208, which defines the standard for SPF mechanisms and processing order.

SPF Record Example ESPs: A Working Sample for SendGrid & Mailchimp

You can use a single SPF record that includes multiple ESPs like SendGrid and Mailchimp by combining their respective mechanisms with your own IP. A valid example is: v=spf1 include:_spf.sendgrid.net include:mailchimp.com ip4:5.6.7.8 ~all. This allows both services to send on your behalf while keeping your own IP trusted. SPF is strict about syntax, so ensure only one SPF record exists per domain. For more on SPF structure, see the official RFC 7208.

How This SPF Record Works

Each include directive references the published SPF rules of a third-party ESP. SendGrid’s policy is published at sendgrid.com/docs/for-developers/sending-email/spf/, and Mailchimp’s is similarly documented in their SMTP setup guides. The ip4:5.6.7.8 entry allows messages from that specific IPv4 address, such as your own internal server or a dedicated email relay. The ~all mechanism means non-listed senders fail soft, which is recommended to avoid overblocking legitimate traffic.

Let’s walk through the components: v=spf1 declares the version, essential for parsing. include:_spf.sendgrid.net says “trust SendGrid’s list of authorized senders.” include:mailchimp.com does the same for Mailchimp. ip4:5.6.7.8 adds your own send IP. ~all is the fallback, marking any other sender as not authorized but not failing hard. This setup prevents your emails from being flagged as spoofed.

Why SPF Matters for ESP Integration

Misconfigured SPF is a top reason for email deliverability issues. If you use both SendGrid and Mailchimp to send transactional or marketing emails, combining them in one record avoids duplication and keeps your domain’s reputation cleaner. Too many SPF records (or overly permissive ones) can lead to alignment failures, especially when receiving systems validate against standards like DMARC. You can test your SPF setup using tools like MxToolbox to verify the syntax and include structure.

If you’re managing complex send environments across multiple ESPs, you may hit the 10 include limit in SPF, which can be problematic. In such cases, consider using a forwarder service or consolidating via a single ESP that supports multiple sub-senders. For quick, accurate checks of your sender list and deliverability health, you can use MailTester’s bulk verification or API checker to validate sender domains and flag potential issues before sending.

Compliance Rules: What's Allowed and What Breaks SPF

You can only have one SPF record per domain in DNS. Trying to add multiple records causes DNS errors and breaks email authentication. Use include mechanisms to consolidate ESPs, but remember each one counts toward the 10 DNS lookup limit. Avoid all or redirect unless you fully understand their impact — they can reject legitimate emails. Instead, use ~all (softfail) or ?all (neutral) to reduce delivery risk and allow more flexibility.

SPF Rule Enforcement: What to Watch For

  • Only one SPF DNS record per domain is allowed — exceeding this causes validation failures.
  • Each include mechanism (e.g. include:_spf.sendgrid.net) counts as a DNS lookup, up to a maximum of 10.
  • Using -all (fail) blocks all mail not explicitly authorized, which can break legitimate deliverability if you miss a service.
  • Prefer ~all (softfail) or ?all (neutral) to let emails pass even if SPF isn’t fully aligned, reducing false bounces.
  • Never use redirect or fail mechanisms unless you’ve tested with trusted tools like MXToolbox or RFC 7208, which define SPF syntax and behavior.
  • Keep your SPF record simple: combine includes with care, and test the full chain with real tools before deploying.

Real-World SPF Testing: Verify Your Setup

Even small mistakes in SPF can lead to rejection by receivers — especially when sending through multiple ESPs. Use inbox placement testing to see how your SPF configuration plays out across real inboxes. You’ll find out if your emails are being silently filtered or marked as spam, even if your DNS checks look clean.

For bulk senders, check your list with MailTester’s bulk verification to catch invalid or risky addresses caused by misconfigured SPF records. The tool flags known problems — like catch-all emails or disposable domains — that can also be linked to authentication failings.

Why You Shouldn't Just Add Multiple SPF Records

You can’t have multiple SPF records for a single domain—DNS allows only one SPF TXT record per domain. Trying to add more than one, even if each is valid on its own, causes SPF validation to fail because SPF checks follow strict parsing rules. The result is a failed authentication, which harms deliverability regardless of how you configure the records.

SPF Record Limits: It’s Built Into the Protocol

SPF is defined in RFC 7208, which explicitly states that only one TXT record per domain should contain an SPF mechanism. If you try to add multiple SPF records, the DNS resolver doesn’t merge them—instead, it sees two conflicting SPF declarations, leading to a permanent failure. This isn’t a mistake by ESPs; it’s the standard behavior defined by the protocol itself.

Let’s say you manage a business that uses both SendGrid and Mailchimp. You might think, “I’ll just add an SPF record for each.” That won't work. Even if both records individually pass SPF syntax checks, the presence of multiple records triggers a failure. This is not a loophole—it’s a core part of how SPF validation operates.

How to Fix It: Use SPF Mechanisms, Not Multiple Records

The correct solution is to include all required sending sources inside a single SPF record using mechanisms like include:. For example:

v=spf1 include:sendgrid.net include:mailchimp.com ~all

This single record authorizes both SendGrid and Mailchimp to send on your behalf. You can test how this applies across your email infrastructure using real inbox placement tools. It’s not just about compliance—proper SPF configuration reduces bounce rates and improves sender reputation.

Many teams overlook this detail until they start seeing deliverability issues. Testing your domain’s SPF setup with tools that check DNS records and simulate real inbox filtering helps avoid surprises. Tools like MailTester's inbox placement tester can simulate real-world conditions across major email providers without sending a single campaign.

Even when using multiple ESPs, you don’t need multiple records. You need one well-structured record that includes all relevant sources. This is how industry-standard SPF configurations work. For large-scale list maintenance, a bulk verification tool like MailTester’s list verification helps you identify bad addresses early—before they harm your domain’s reputation through bounces or spam complaints.

How to Test Your SPF Record After Setup

After configuring your SPF record for multiple ESPs, test it in real-world conditions: send sample emails from each ESP using a tool like MailTester to verify deliverability, inspect the actual DNS record with a public validator, and confirm inbox placement. Don’t rely on configuration alone—real delivery is the only proof.

Test SPF pass/fail with real email sends

  • Use MailTester’s real-time verification API to send test emails from each ESP you’re using (e.g., SendGrid, Mailchimp, Amazon SES) and check the SPF result in real time.
  • Run a bulk verification on a sample list via MailTester’s bulk list verification to check SPF compliance across hundreds of addresses at once.
  • Look for "SPF: Pass" or "SPF: Fail" in the verification report — this tells you whether the receiving server accepts your sending domain’s authorization.

Verify the DNS record and delivery results

  • Copy your final SPF record and validate it using a public DNS checker like MXToolbox or DNSChecker.org to catch syntax errors or unintended inclusion of non-authorized ESPs.
  • Ensure the record stays under 250 characters and includes no more than 10 mechanisms (including includes), per RFC 7208 standards — exceeding this causes failures.
  • Test inbox placement using MailTester’s inbox placement tool to see how your message lands in Gmail, Outlook, Yahoo, and other major providers.
  • Review the delivery logs from each ESP (e.g., SendGrid’s delivery reports) to confirm no bounces related to authentication issues.
SPF isn’t a one-time setup. Monitor it quarterly and after any change to your email stack.

Even if the record parses correctly in a DNS tool, email can still fail due to greylisting, rate limiting, or sender reputation. Always test end-to-end: setup, sending, receiving, and inbox placement. Use MailTester’s integrations with platforms like Mailchimp and Klaviyo to automate verification into your workflow. Start with 100 free verifications at MailTester’s pricing page to validate your setup with confidence.

How MailTester Helps Validate SPF and Deliverability

You can validate SPF records for multiple ESPs and test overall deliverability with MailTester by running real-time checks on individual addresses or entire lists. It probes your domain’s SPF, DKIM, and DMARC alignment, checks sender reputation, and simulates inbox placement across Gmail, Outlook, and Apple Mail—so you see how your emails are treated before sending.

Verify SPF and Infrastructure Health

SPF records can get messy when using multiple ESPs. Misconfigurations here cause bounces, even if the email address is valid. MailTester checks your SPF record against the actual sending domains to ensure no conflicts exist. If your domain sends via both SendGrid and Mailchimp, for example, MailTester confirms the SPF record properly includes both. This reduces the risk of rejection due to alignment failures.

Our verification process goes beyond basic syntax checks. It validates whether SPF mechanisms actually permit each sending service, based on real-time DNS lookups and standardized checks laid out in RFC 7208. You’re not just looking at a syntax validator—you’re testing whether your configuration works in practice.

Test Deliverability Before You Send

Even with a correct SPF record, your email can still land in spam. This happens due to sender reputation, content signals, or inbox filtering behavior. MailTester’s inbox-placement test simulates delivery to major inboxes, giving you a clear read on how likely your message is to reach a real user’s primary inbox.

Use the inbox placement tester to evaluate your campaign’s chances before sending to a large list. It checks how Gmail, Outlook, and Apple Mail respond—not just based on headers, but on real-world inbox filtering patterns. This lets you catch issues early, before they impact your sender reputation.

Whether you're managing a list for newsletter campaigns or transactional sends, MailTester gives you insight into the full stack: DNS configuration, domain health, and inbox acceptance. It's like running a health check on your entire delivery pipeline.

Start with bulk list verification or use our real-time API for on-the-fly validation. Your first 100 verifications are free, and credits never expire. Use it to test SPF for multiple ESPs—or any send setup—and send with confidence.

Common Mistakes When Combining SPF for Two Providers

Combining SPF for multiple ESPs isn’t just about listing them—it’s about avoiding common pitfalls that break deliverability. You risk overloading the DNS lookup limit, unintentionally blocking valid sends, or creating a record that fails validation. The key is precision: every include, mechanism, and alignment must be intentional and up to date.

Spot the Real Issues in Your SPF Record

  • Don’t include ESPs you no longer use—outdated providers waste lookup slots and increase failure risk. If you switched from SendGrid to Mailgun, remove the old include:sendgrid.net entry.
  • Don’t pile up include mechanisms without checking the total DNS lookup count. Each include counts against the 10-lookup limit defined in SPF RFC 7208. Too many leads to a permanent fail.
  • Never add all without testing. Using ~all (softfail) or -all (hardfail) affects how receivers treat your emails. Testing with tools like MXToolbox helps validate the outcome before deployment.
  • Don’t neglect to update the SPF record after changes. If you add or remove one ESP, the record must change immediately—delayed updates cause bounce spikes and sender reputation damage.

How to Stay Ahead of SPF Problems

Let’s make it simple: before you publish a new SPF record, validate its structure. Use a real-time SPF validator or run a test on RFC 7208—the official standard—for proper syntax. If you're using multiple ESPs, test every variation in your staging environment.

Many teams miss the point that SPF alignment works only when your From domain matches the spf domain. Misalignment—common when using ESPs with subdomain relays—can break email trust signals even if the SPF record is technically correct.

Use an email verification tool to catch invalid or risky addresses before they reach your ESPs. That way, you’re not just managing SPF—it’s part of a larger deliverability health check. Try bulk verification to clean your list and avoid sending to domains with bad SPF setups.

What to Do If Your SPF Record Still Fails

Even after updates, an SPF record may fail due to overlapping or malformed entries. The most common cause is having multiple SPF TXT records in DNS. Only one SPF record should exist per domain.

Check for Parsing Errors

Use a tool like MxToolbox to analyze your TXT record. It will show if the record parses correctly or contains syntax issues that prevent proper validation.

Review Include Mechanisms

Ensure all include mechanisms point to active, valid ESPs. Deprecated or incorrect include values can break SPF alignment and lead to failed validation.

Full sending health goes beyond SPF. Run a complete check that includes DKIM, DMARC, domain reputation, and inbox placement — all in one test.

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Frequently asked questions

Can I have two SPF records for one domain?

No. Only one SPF TXT record is allowed per domain. Multiple records cause SPF validation to fail.

How many include mechanisms can I have in an SPF record?

You can have up to 10 'include' mechanisms before reaching the DNS lookup limit.

What happens if my SPF record exceeds the 10 lookup limit?

The SPF check fails, which may result in email rejection by receiving servers.

Should I use -all or ~all in my SPF record?

Use ~all (softfail) to allow some margin for error, especially when multiple ESPs are involved.

Does MailTester test SPF records directly?

No, but it includes SPF checks as part of its inbox placement and deliverability tests.

Can I use MailTester to verify if my SPF setup is correct?

Yes. MailTester can validate email addresses and test deliverability, including SPF, DKIM, and DMARC compliance during real sending tests.

Does combining SPF for multiple ESPs affect sender reputation?

Improper SPF setup harms sender reputation. Correctly combined SPF maintains deliverability and trust.

What if one ESP doesn’t provide an SPF include?

If an ESP doesn’t support SPF inclusion, use their recommended IP range with 'ip4' instead.

How often should I audit my SPF record?

Review your SPF record every time you add or remove an ESP, or after significant delivery issues.

Are there any tools to help manage SPF records with multiple ESPs?

Yes. MailTester’s verification API and inbox placement tests help validate SPF compliance during real sends.

What’s the difference between SPF, DKIM, and DMARC?

SPF verifies sender IP legitimacy; DKIM signs email content; DMARC enforces policies from SPF and DKIM.

Can I include both SendGrid and Mailchimp in one SPF record?

Yes, as long as the total number of DNS lookups doesn’t exceed 10 and the record is correctly formatted.