Outsmart Email Spoofers With SPF

Modifiers define the SPF policy:

• ~all for soft fail (mark spam but accept)
• -all for hard fail (reject email)
• ?all for neutral result
• +all to explicitly permit all IPs

For example, a record could look like:

v=spf1 ip4:192.168.1.1 ip6:2001:0db8:85a3 ~all

This authorizes the IPv4 and IPv6 addresses listed and assigns ~all for unknown IPs.

Now let's look at how SPF thwarts spammers in a real-world example.

How SPF Defended Company X Against Email Spoofing

Company X was frequently seeing spoofed spam emails being sent from [email protected] addresses. To stop this impersonation, they added this SPF record to their DNS:

v=spf1 ip4:192.168.1.100 ip4:192.168.1.101 ~all

This lists their two mail server IPs. When a spoofed email arrived appearing to come from [email protected] over IP 75.40.1.50, the receiving server performed an SPF check.

It looked up the SPF record for companyx.com and saw the email's source IP did not match. Per the ~all modifier, it soft failed SPF and marked the message as spam instead of rejecting it outright.

Company X was spared the reputation damage of an outright spoofed email rejection. The spam filter tagging also deterred the spoofers from continuing their efforts.

This example shows how proper SPF record setup can turn the tables on email spoofing.

Takeaways on How SPF Works

• SPF records list authorized mail servers in DNS
• Receivers check them to verify legitimate emails
• Spoofed emails from unauthorized servers fail SPF
• Spammers are deterred knowing they'll be caught

Now that you know the ins and outs of SPF records, let's look at how to add them to safeguard your own domain…

Setting Up SPF with Popular Email Providers

Now that you understand what SPF is and how it works, let's look at configuring SPF records with some of the top email services - GoDaddy, SendGrid, and Amazon SES.

Configuring SPF Records in GoDaddy

Many businesses use GoDaddy for hosting their domain DNS records. Here's how to add an SPF record if you use GoDaddy.

Step-by-Step Guide for GoDaddy SPF Setup

Generating the SPF Record Value

First, you need to create the SPF record text. For GoDaddy's own email products like Microsoft 365 or Workspace Mail, use:

v=spf1 include:secureserver.net ~all

If you're using additional email senders beyond GoDaddy's servers, include them like this:

v=spf1 include:secureserver.net include:otherserver.com ~all  

Adding the TXT Record in GoDaddy DNS

Once you have the SPF record value, follow these steps:

1. Log into your GoDaddy account and access your domain's DNS settings.
2. Click "Add" to create a new record.
3. Select "TXT" for the type.
4. Enter "@" for the Host field.
5. Paste your SPF record value into the TXT Value field.
6. Set a short TTL of 1 hour.
7. Click "Save" and you're done!

It may take up to 48 hours to propagate the new SPF record across DNS servers.

Troubleshooting GoDaddy SPF Issues

If you run into any problems with your GoDaddy SPF record, double check that:

• There are no typos in the SPF syntax
• The TXT record is under the base domain, not subdomain
• There is only one SPF record for your domain
• You didn't add any blank spaces

This should get your GoDaddy SPF record up and running smoothly.

SPF Setup Guide for SendGrid Users

SendGrid customers will need to take a couple short steps to activate SPF protection.

Obtaining Your Unique SendGrid SPF Record

SendGrid provides the SPF TXT record you need in your account dashboard. Navigate there and you'll find it under Settings > Sender Authentication.

It will look similar to:

v=spf1 include:sendgrid.net ~all

This covers SendGrid's IPs with include:sendgrid.net.

Adding the SPF TXT Record in Your DNS

Take this SPF record and add it as a TXT entry in your domain's DNS records. The steps are the same as with GoDaddy above:

1. Choose TXT as the record type
2. Enter "@" as the Host
3. Paste in your unique SendGrid SPF record for the TXT Value
4. Use a short TTL of 1 hour

Once added to your DNS, SendGrid's IPs will be authorized to send mail from your domain.

SendGrid SPF Best Practices

Keep these SendGrid-specific tips in mind:

• Only add the SPF record SendGrid provides - don't modify or expand it.
• Disable any legacy Sender ID records - they are outdated.
• If you disable automated security, manage CNAME records instead of TXT.

Stick to these best practices and your SendGrid SPF record will be protecting your domain in no time.

How to Add an SPF Record for Amazon SES

For Amazon SES users, here is how to easily publish an SPF record.

Getting Your Amazon SES SPF Record Value

Navigate to the SMTP Settings section of your Amazon SES dashboard. Then click "Show SPF Record" to reveal the TXT entry:

v=spf1 include:amazonses.com ~all

This covers Amazon's authorized IPs.

Adding the SPF TXT Entry to Your DNS

Take this SPF record value and add it as a TXT record in your domain's DNS management:

1. Select TXT as the type
2. Use "@" as the Host
3. Enter the full SPF record in the TXT Value field
4. Set the TTL to 1 hour

That's all it takes to activate SPF protection for your Amazon SES emails.

Verifying Your Amazon SES SPF Record

Give the DNS changes time to propagate fully across servers. Then you can check that the record is present by querying your domain's TXT records using the dig command:

dig domain.com txt

This will display all TXT records for your domain. Verify that the Amazon SES SPF record is now listed and properly formatted.

With these steps complete, your Amazon SES emails will pass SPF checks and avoid spoofing. Just remember to update the record if you add new sending IPs in the future.

SPF Management Tips and Common Questions

Setting up an SPF record is the first step, but ongoing maintenance is important for keeping your protection effective. Here are some top tips for managing your SPF records plus answers to frequent questions.
Updating SPF Records When Adding New Senders

If you start using new email servers or third-party sending services, remember to update your SPF record to authorize them.

For example, if you use SendGrid and then add MailChimp for email marketing, revise your SPF record:

Original: 
v=spf1 include:sendgrid.net ~all

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

Whenever a new sender is added, rerun the SPF record generator to create an updated, consolidated policy. Then change the SPF record in your DNS management.

Fixing Common SPF Errors Like PermError

If your SPF record is formatted incorrectly, some common errors like permerror may appear in SMTP logs.

A permerror indicates a permanent syntax error that's rejecting all email as spam. Fix these ASAP by correcting issues like:

• Missing or invalid syntax like v-spf1
• Typos in mechanisms like ip4:
• Too many DNS lookups exceeding 10 maximum
• Multiple, conflicting SPF records

Use an SPF validator tool to identify and fix problems.

SPF Limitations and Lookup Limits

SPF records have a few technical restrictions to keep in mind:

• The published record can only be 255 characters maximum
• SPF checks are limited to 10 DNS lookups to prevent abuse
• Lookups from include mechanisms count toward the 10 lookup limit

Exceeding 10 DNS lookups will result in the permerror previously mentioned. Flatten your SPF record if needed to stay under the limit.

Should You Have Multiple SPF Records?

No - do not publish multiple SPF records for your domain. Only one SPF record is allowed.

If you add multiple SPF records, authentication issues will occur and your deliverability may suffer. Delete any duplicate records.

However, you can publish unique SPF records on subdomains. The main domain has its own SPF record, and each subdomain can have a custom SPF tailored to its specific sending configuration.

Just don't create two overlapping SPF records both on the primary root domain.

How to Change or Remove an Incorrect SPF Record

If your current SPF record is incorrect or needs to be updated, first add the new corrected version in your DNS management console.

Once the new record is published and propagated, you can go back and safely delete the outdated entry. This ensures no disruption in protections during the transition.

Sometimes an invalid SPF record gets published that needs to be completely removed rather than updated. Follow the same steps - first publish a proper placeholder record like v=spf ~all, then delete the bad record once the new one is active.

Best Practices For Ongoing SPF Management

To keep your SPF records running smoothly:

• Revalidate your SPF syntax whenever errors appear
• Check new IPs are authorized before sending
• Update your SPF if you migrate ESPs or DNS providers
• Monitor DNS propagation after making SPF changes
• Keep records current as you add or change mail servers

Proper ongoing management will ensure your SPF configuration remains optimized over time.

Takeaways and Next Steps for SPF Success

With your SPF records now configured and optimized, let's recap the key benefits of SPF and additional steps to enhance your email protection even further.
Main Benefits of Adding SPF Records

Activating SPF provides these advantages:

• Prevents spoofing - SPF rejects illegitimate emails impersonating your domain from unauthorized servers.
• Boosts deliverability - Legitimate emails that pass SPF are less likely to be blocked or labelled as spam.
• Deters spammers - Knowing spoofing attempts will fail makes your domain a less attractive target.
• Improves security - Reduced spoofing lowers risk of phishing, fraud, account takeovers.
• Enhances compliance - SPF demonstrates domain ownership for reporting needs.
• Increases trust - Recipients have confidence in the validity of your emails.
• Easy to implement - SPF records are fast and simple to activate.
• Low maintenance - Occasional updates are quick when adding new senders.

Don't leave your domain vulnerable - take advantage of these benefits with SPF.

Best Practices for Ongoing SPF Management

Keep your SPF records current and optimized using these management tips:

• Periodically revalidate your SPF syntax for issues
• Promptly update your SPF as you onboard new mail servers
• Monitor DNS propagation when making SPF changes
• Consolidate records if adding subdomains
• Watch for SPF errors or flagging and adjust accordingly
• Keep records consistent across DNS hosting providers
• Document your SPF configuration steps for easy troubleshooting

Following SPF best practices will maximize uptime and prevent authentication problems.

Using SPF Alongside DKIM and DMARC for Deliverability

For optimal email protection, use SPF as part of a layered authentication approach:

• SPF verifies authorized sending servers
• DKIM confirms signed emails from your domain
• DMARC enhances spoofing protection and reporting

Together, these technologies provide overlapping layers of security, bolstering the validity of your emails.

Activating all three requires some additional effort but is well worth it for your reputation and compliance.

How SPF Contributes to Email Security and Compliance

SPF is a key component of a secure email environment:

• SPF records act as a safeguard against business email compromise attacks.
• Passing SPF helps satisfy authentication requirements for regulators.
• Maintaining SPF aligns with cybersecurity frameworks and standards.
• The identity validation assists with fraud reduction and risk management.
• SPF builds user and partner trust by demonstrating security commitments.

Given the importance of email communication, make certain your domains have SPF protection enabled.

Summary on Setting Up SPF Records

After reading this comprehensive guide on configuring SPF records, keep these main tips in mind:

• SPF records verify authorized sending servers to stop email spoofing and spam. They provide a vital layer of protection for your domain.
• Major email providers like GoDaddy, SendGrid, and Amazon SES have summarized, pre-generated SPF records available for easy setup.
• For other services, SPF records can be manually created using permissible mechanisms like ip4: and include:.
• Only one SPF record can be published on a domain. subdomain SPF records don't count toward this limit.
• Adding new senders requires updating your SPF records to avoid deliverability issues.
• Fix common SPF errors like "permerror" by validating and correcting your SPF syntax.
• Use SPF checker tools to diagnose issues and optimize your record formatting.
• Layer SPF with DKIM and DMARC for overlapping email authentication and security.
• Maintain your SPF records proactively to maximize uptime and prevent problems.

Effective SPF configuration takes your email protection and compliance to the next level. Now that you understand the ins and outs of SPF records, it's time to start safeguarding your own domains.

Frequently Asked Questions About SPF

Still have some lingering questions about SPF records and how they work? These common FAQs should help provide clarification:
What happens if I don’t set up SPF?

Without SPF, your domain is vulnerable to spoofing, phishing, and spam. Emails are more likely to be flagged as spam or rejected.

Does SPF guarantee all my email gets delivered?

No. SPF verifies your emails, but deliverability also depends on factors like sender reputation, content, and recipient filters.

How long does it take for an SPF record to activate?

It can take up to 48 hours for a new SPF record to fully propagate across DNS servers. Email services may take additional time before utilizing your updated SPF policy.

Can I use multiple SPF records on subdomains?

Yes, you can use distinct SPF records on subdomains. Just avoid publishing more than one SPF record on the root domain.

What happens if my SPF record is formatted wrong?

Incorrect SPF syntax often produces “permerror” causing all mail to fail. Validate your SPF record format whenever errors appear.

Why am I hitting the SPF lookup limit?

SPF has a 10 DNS lookup maximum to prevent abuse. “Include” mechanisms contribute to this limit. Flatten your record if exceeding it.

How do I update my SPF when switching email services?

When migrating email providers, add the new SPF record first before deleting the old record to avoid downtime in authentication.