Email authentication is non-negotiable for successful outreach campaigns. Without proper setup, your emails risk being flagged as spam or blocked entirely. The three key protocols - SPF, DKIM, and DMARC - work together to verify your emails are legitimate and protect your domain from phishing and spoofing attacks.
Here’s what you need to know:
Why it matters:
Quick Steps to Get Started:
Proper setup not only protects your domain but also improves email deliverability, ensuring your messages land in inboxes - not spam folders.
Setting up SPF, DKIM, and DMARC without preparation can lead to email delivery issues, authentication failures, and a lot of troubleshooting headaches. A well-prepared infrastructure ensures a smoother setup process and strengthens your email authentication framework, which is essential for successful cold outreach.
Here’s how to get your domain ready for SPF, DKIM, and DMARC configuration.
Start by creating a detailed list of all the services, servers, and platforms that send emails on behalf of your domain. This step is crucial because your SPF record will rely on this inventory to define which IP addresses are authorized to send emails.
Include email service providers like SendGrid, Mailchimp, Google Workspace, Microsoft 365, Amazon SES, and Postmark, as well as marketing tools such as HubSpot and Salesforce. Don’t forget to document all sending domains and subdomains (e.g., yourcompany.com, mail.yourcompany.com) along with their associated IP addresses or SPF include statements.
To keep things organized, use a spreadsheet with the following columns:
This documentation will be a lifesaver when setting up SPF records or troubleshooting email delivery problems.
Since email authentication requires updating DNS records, you’ll need administrative access to your DNS management panel. The process for accessing DNS settings depends on where your domain is registered or hosted.
Log into your domain registrar’s account (e.g., GoDaddy, Namecheap, Network Solutions) or DNS hosting provider (e.g., Cloudflare, Route 53, Google Cloud DNS). Look for the section labeled "DNS Management" or something similar. If you can’t find it, you may need to reach out to your IT team or hosting provider for assistance.
Once you locate your DNS settings, verify your access by reviewing the existing records. You should see entries like A, CNAME, MX, and possibly TXT records. If you can view these records but can’t edit them, make sure to request elevated permissions before proceeding.
For organizations using Microsoft 365, there are specific instructions available for connecting DNS records with providers such as IONOS, GoDaddy, or Namecheap. Use reliable tools - either online or command-line - to verify your DNS records before making changes.
After confirming access, audit your current DNS records to identify any potential issues. Misconfigured DNS settings can result in email failures, website downtime, or other disruptions.
Focus on reviewing TXT, MX, and CNAME records to spot outdated entries, conflicts, or duplicate records. Look specifically for entries starting with "v=spf1", "v=DKIM1", or "v=DMARC1". For SPF records, ensure there’s only one per domain, as multiple SPF records can lead to authentication errors.
Check for old IP addresses in your SPF records that no longer correspond to active email servers or services. Remove these outdated entries to reduce security risks and avoid unnecessary complications.
Regular audits of your DNS records help protect against cyber threats and improve email deliverability. Document any inconsistencies or outdated entries you find, and clean up your DNS zone files before adding new authentication records.
If your infrastructure is particularly complex, consider using tools like Infraforge. These platforms can automate DNS setup and provide dedicated email infrastructure, reducing the risk of errors and ensuring better deliverability for your outreach campaigns.
Once you've audited your DNS records and prepared your infrastructure, it's time to configure your email authentication protocols. Setting up SPF, DKIM, and DMARC correctly is essential to ensure your emails are authenticated and delivered successfully.
Start your SPF record with the version tag v=spf1, which must always come first. After that, list your authorized sending sources. Use include statements for email service providers or ip4/ip6 mechanisms for specific IP addresses. For example, if you're using Google Workspace and Mailgun, your SPF record might look like this:
v=spf1 include:_spf.google.com include:mailgun.org -all.
Pay close attention to the 10 DNS lookup limit, as exceeding it will cause SPF authentication to fail. Each include statement counts as one lookup, so if you're nearing the limit, consider consolidating email providers or using SPF flattening services.
Avoid common mistakes that can break your SPF setup. For instance:
| Common SPF Issue | Incorrect SPF Record | Fixed SPF Record |
|---|---|---|
| Multiple SPF records | v=spf1 include:_spf.google.com -all v=spf1 include:spf.mailgun.org -all |
v=spf1 include:_spf.google.com include:spf.mailgun.org -all |
| Too Many DNS Lookups | v=spf1 include:_spf.google.com include:spf.mailgun.org include:spf.sendgrid.net include:spf.salesforce.com include:spf.constantcontact.com -all |
v=spf1 include:_spf.google.com include:spf.mailgun.org -all |
| Syntax Errors | v=spf1 include:_spf.google.com include:spf.mailgun.org all |
v=spf1 include:_spf.google.com include:spf.mailgun.org -all |
Once you've published your SPF record, validate it using SPF record checkers. These tools confirm that your syntax is correct and ensure you haven't exceeded the lookup limit. They also verify that your record resolves properly across DNS servers.
With your SPF setup complete, you can move on to configuring DKIM to enhance email security.
DKIM (DomainKeys Identified Mail) protects the integrity of your emails by adding a cryptographic signature. While the specific steps vary by provider, the overall process is similar.
Most email platforms - like SendGrid, Mailchimp, and Amazon SES - offer tools to automate DKIM setup. Typically, you'll generate a DKIM key pair from your provider's dashboard. Then, you'll publish the public key as a TXT record in your DNS. The record name usually follows the format selector._domainkey.yourdomain.com, with the selector being a unique identifier provided by your email service.
When setting up DKIM, avoid common pitfalls:
v=DKIM1 and includes the p tag for the public RSA key. Use semicolons to separate tags and specify SHA-256 as the hash algorithm with h=sha256.For organizations with multiple email providers, each service may require a unique DKIM selector and key pair. Keep detailed records to prevent conflicts and simplify key rotation when necessary.
After setting up SPF and DKIM, DMARC (Domain-based Message Authentication, Reporting, and Conformance) ties everything together by enforcing your domain's authentication policy. Start with a monitoring mode to gather insights before moving to stricter enforcement.
A basic DMARC record for monitoring might look like this:
v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; pct=100.
Here’s what the tags mean:
p=none: Enables monitoring without affecting email delivery.rua: Specifies where aggregate reports should be sent.pct=100: Applies the policy to all emails.These reports offer valuable data on which emails pass or fail SPF and DKIM checks, helping you spot potential issues. Once you're confident your legitimate email sources are properly authenticated, gradually increase enforcement:
p=none to p=quarantine to send suspicious emails to spam folders.p=reject to block unauthorized emails entirely.Less than 20% of domains currently enforce DMARC policies at the highest level, leaving many vulnerable to spoofing. To avoid common DMARC setup errors:
sp=quarantine or sp=reject to protect subdomains.pct=100 to ensure your policy applies to all emails.Validate your DMARC setup using online tools and test services like check@dmarcly.com. Regularly reviewing DMARC reports helps you catch and fix issues before they disrupt your email campaigns.
Once you've set up SPF, DKIM, and DMARC, the work isn't over. Keeping your email system running smoothly requires ongoing maintenance and monitoring to ensure email integrity and avoid deliverability hiccups.
Email authentication isn’t a “set it and forget it” process. Regular audits are essential:
"SPF is not a one-time job - you practically have to keep checking your SPF record to ensure it's appropriately configured."
Set up a routine to review your SPF, DKIM, and DMARC configurations. During these audits, analyze your DMARC reports weekly to identify any failing sources and make necessary updates to your SPF records.
Keep a clear record of DNS changes. A simple spreadsheet noting the date, record type, old and new values, and the reason for each change can make troubleshooting much easier.
When switching email providers or updating your infrastructure, remove outdated sending sources from your SPF records. Leaving old entries in place can clutter your records and exceed the 10 DNS lookup limit, which can lead to SPF failures.
It’s also a good idea to use DNS validation tools to catch any syntax errors or misconfigurations. Tools like MXToolbox, DMARC Analyzer, and SPF Record Check can help uncover issues that might slip through manual reviews.
By conducting these regular audits, you can ensure your email authentication remains effective and your deliverability stays on track.
After your DNS records are in good shape, real-time monitoring becomes your next line of defense. With phishing attacks affecting 94% of organizations in 2023, keeping an eye on email security and deliverability is more important than ever.
Several platforms make monitoring easier:
To stay ahead of potential problems, review DMARC aggregate and forensic reports weekly. For example, a SaaS client working with SalesHive managed to cut their spam complaint rate by 41% in just 90 days by shifting from a p=none policy to p=reject, guided by insights from DMARC reports.
As your email campaigns grow, managing DNS records and deliverability across multiple domains can become a real challenge. That’s where advanced solutions like Infraforge come in.
Infraforge simplifies the process with automated DNS setups for SPF, DKIM, and DMARC, following industry best practices. The platform can configure a domain and mailbox in as little as 5 minutes - much faster than manual setups.
Infraforge also offers features tailored for scaling, including bulk DNS updates and scalable pricing. Each mailbox gets a dedicated IP, which helps protect your deliverability from being affected by other senders’ reputations. Plus, their monitoring and alert system ensures you’re immediately notified of any authentication issues.
As Silver L, CEO, puts it:
"Infraforge quickly helped to solve a challenge regarding email deliverability. What I like about Infraforge is its ease of use and quality of support."
The platform also supports domain masking with SSL proxies, which helps safeguard your primary brand during outreach campaigns. And the benefits of using DMARC and DKIM are clear: organizations using DMARC see 90% fewer successful phishing attempts, while DKIM reduces email tampering by 30%.
Once you've set up your SPF, DKIM, and DMARC records and established monitoring systems, the next step is to ensure everything is functioning correctly before launching your outreach campaigns.
v=spf1. It should include all authorized email-sending sources and stay within the 10 DNS lookup limit. Avoid having multiple SPF records for a single domain, as this can cause failures.
selector._domainkey.yourdomain.com.
_dmarc.yourdomain.com. Start with a policy of p=none for monitoring purposes, and once authentication success rates improve, transition to p=quarantine or p=reject for stricter enforcement.
Double-check your DNS records to verify proper formatting, spacing, and syntax.
To confirm your setup, external tools like MXToolbox are invaluable. They can validate your records, identify syntax errors, and ensure everything is correctly published.
For a deeper analysis, DMARCLY offers a straightforward testing method: send an email from your domain to check@dmarcly.com, and you'll receive a detailed report on your SPF, DKIM, and DMARC configurations. Similarly, EasyDMARC can automatically detect DKIM keys using predefined selectors, simplifying the validation process.
You can also send test emails to services like Gmail, Outlook, and Yahoo, then review the email headers for 'Received-SPF' and 'Authentication-Results' to confirm they pass . Allow time for DNS propagation before rechecking your setup.
It’s worth noting that occasional issues may still arise. For instance, in November 2023, a Microsoft 365 user reported SPF and DKIM success rates of about 97%, with another user attributing occasional failures to Microsoft’s DNS timeouts when querying records.
Successful tests indicate your system is ready for live outreach.
Proper verification of SPF, DKIM, and DMARC ensures better email deliverability and protection against spoofing. Completing this step finalizes your authentication setup and prepares your infrastructure for continuous monitoring.
Managing multiple domains or scaling outreach can make manual DNS management challenging. Automated tools like Infraforge can simplify this process, configuring domains and mailboxes in just minutes while following industry standards.
Keep in mind that authentication isn’t a one-and-done task. Regularly monitor your DMARC aggregate reports to ensure your protocols remain effective. As your email infrastructure grows, automated systems become essential for maintaining consistent deliverability across campaigns.
With a solid authentication setup and ongoing monitoring, you'll have the tools needed to ensure your emails land in inboxes - not spam folders.
SPF, DKIM, and DMARC are key protocols for protecting your email domain and improving deliverability. Here's a quick breakdown:
When these protocols are set up correctly, they work together to enhance your domain's reputation, reduce the chances of your emails being flagged as spam, and shield your brand from phishing or spoofing attempts. For cold email campaigns, this setup is especially important to build trust and ensure your messages reach inboxes instead of spam folders.
When you're setting up SPF, DKIM, and DMARC for the first time, it's easy to stumble into a few common pitfalls that can hurt your email deliverability. Here are some key issues to watch out for:
Taking the time to carefully review and test your setup can save you a lot of headaches. Staying on top of updates and ensuring proper alignment are essential for keeping your email authentication strong and your sender reputation intact.
To keep your email authentication protocols in top shape, it's important to routinely check and update your SPF, DKIM, and DMARC configurations. For added security, make it a habit to rotate your DKIM keys every six months. Additionally, reviewing DMARC reports can help you quickly spot and address any authentication problems before they escalate.
Automated tools can be a game-changer for spotting misconfigurations or detecting unusual activity. They ensure your emails are consistently delivered while protecting against phishing attempts. Infraforge makes this process straightforward with tools like automated DNS setup, pre-warmed domains, and in-depth reporting. These features not only simplify managing email authentication but also help you fine-tune your outreach efforts for better results.