Common DNS Record Issues for Email Deliverability

Common DNS Record Issues for Email Deliverability

DNS record problems are a leading cause of email deliverability issues. Misconfigured, missing, or incorrect DNS records can cause emails to be rejected, filtered into spam, or fail authentication checks. Identifying and fixing these issues is essential for maintaining good inbox placement.

Quick Answer

Common DNS record issues that hurt email deliverability include missing SPF/DKIM/DMARC records, syntax errors, multiple SPF records, misaligned domains, outdated records, and DNS propagation delays. These problems prevent proper email authentication, causing receiving servers to reject or filter your emails as spam.

Why DNS Record Issues Matter

DNS records are the first thing receiving email servers check when processing your emails. If records are missing, incorrect, or misconfigured, servers can't verify that your emails are legitimate. This leads to:

• Rejected emails: Servers may completely reject unauthenticated emails
• Spam filtering: Emails may be filtered into spam folders
• Reputation damage: Repeated authentication failures hurt your sender reputation
• Blacklisting: Severe issues can lead to domain blacklisting
• Lost revenue: Undelivered emails mean missed opportunities

Most Common DNS Record Issues

1. Missing DNS Records

Problem: One or more essential DNS records (SPF, DKIM, DMARC) are not configured.

Impact: Emails fail authentication checks, leading to spam filtering or rejection.

How to identify: Use MailMoxie's DNS Record Checker. Missing records won't appear in the results.

Solution: Add the missing records through your DNS provider's dashboard. Your email service provider should provide the exact records to add.

Example: If SPF is missing, add a TXT record at your root domain with your SPF configuration.

2. Multiple SPF Records

Problem: More than one SPF record exists for your domain.

Impact: Authentication failures because receiving servers don't know which SPF record to use.

How to identify: The DNS checker will show multiple SPF records or authentication failures.

Solution: Combine all SPF includes into a single record. You can only have one SPF record per domain.

Before (incorrect):

Record 1: v=spf1 include:_spf.google.com ~all
Record 2: v=spf1 include:servers.mcsv.net ~all

After (correct):

v=spf1 include:_spf.google.com include:servers.mcsv.net ~all

3. SPF Record Syntax Errors

Problem: SPF records contain typos, missing semicolons, invalid characters, or incorrect formatting.

Impact: SPF validation fails, causing authentication problems.

How to identify: DNS checker will show syntax errors or validation failures.

Common syntax errors:

• Missing v=spf1 at the start
• Typos in include: statements
• Invalid characters or spaces
• Missing ~all or -all at the end
• Exceeding 255 character limit without flattening

Solution: Double-check the SPF record syntax. Use SPF record validators to verify the format is correct.

Example of correct syntax:

v=spf1 include:_spf.google.com include:servers.mcsv.net ~all

4. DKIM Record Misconfiguration

Problem: DKIM record is missing, has incorrect selector, or contains invalid public key.

Impact: Emails fail DKIM authentication, reducing trust with receiving servers.

How to identify: DKIM checks fail in email headers or deliverability reports.

Common issues:

• Wrong selector (e.g., using default when provider uses selector1)
• Invalid public key format
• Missing DKIM record entirely
• Key mismatch between signing and DNS records

Solution: Verify the correct selector and public key from your email service provider. Ensure the DKIM record is at the correct subdomain.

5. DMARC Policy Misalignment

Problem: DMARC record has incorrect policy settings, missing reporting addresses, or syntax errors.

Impact: DMARC validation fails, preventing policy enforcement and reporting.

How to identify: DMARC checks fail, or you don't receive DMARC reports.

Common issues:

• Missing v=DMARC1 version tag
• Invalid policy value (must be none, quarantine, or reject)
• Missing or invalid reporting email addresses
• Syntax errors in the record

Solution: Verify DMARC syntax and ensure reporting addresses are valid email addresses.

Example of correct DMARC:

v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; ruf=mailto:dmarc@yourdomain.com

6. Domain Misalignment

Problem: SPF or DKIM records don't align with the "From" domain in your emails.

Impact: DMARC fails because SPF/DKIM alignment is required for DMARC to pass.

How to identify: DMARC reports show alignment failures even when SPF/DKIM pass individually.

Common causes:

• Sending from a subdomain but SPF/DKIM configured for root domain
• Using a different domain in "From" address than DNS records
• SPF record doesn't include the sending service

Solution: Ensure DNS records match the domain used in your "From" address, or configure records for subdomains if sending from subdomains.

7. Outdated or Stale Records

Problem: DNS records reference services you no longer use or contain outdated information.

Impact: Authentication may fail if old services are removed, or security risks if old records remain.

How to identify: Records include services you've discontinued or don't recognize.

Solution: Regularly audit DNS records and remove references to services you no longer use. Update records when changing email providers.

8. DNS Propagation Delays

Problem: DNS changes haven't propagated globally yet, so some servers see old records.

Impact: Inconsistent authentication results until propagation completes.

How to identify: Some checks show new records while others show old or missing records.

Solution: Wait 24-48 hours for full DNS propagation. Use DNS propagation checkers to verify changes have spread globally.

9. Record Length Limits

Problem: SPF record exceeds 255 characters, causing validation issues.

Impact: SPF validation may fail or be truncated, leading to authentication problems.

How to identify: SPF record is very long (over 255 characters) or shows truncation warnings.

Solution: Use SPF flattening services or consolidate includes. Some DNS providers support longer records, but 255 characters is the standard limit.

10. Incorrect MX Record Priority

Problem: MX records have incorrect priority values or missing backup servers.

Impact: Email delivery failures if primary server is unavailable.

How to identify: MX record checks show incorrect priorities or missing redundancy.

Solution: Ensure primary MX has lowest priority number (e.g., 1 or 10), with backup servers at higher priorities (e.g., 20, 30).

How to Diagnose DNS Record Issues

Step 1: Use DNS Record Checker

Run MailMoxie's DNS Record Checker on your domain to get a comprehensive analysis of all DNS records.

Step 2: Review Error Messages

Look for specific error messages that indicate what's wrong:

• "SPF record not found"
• "Multiple SPF records detected"
• "DKIM signature failed"
• "DMARC policy not configured"

Step 3: Check Email Headers

Send a test email and review the authentication headers:

• Authentication-Results header shows SPF, DKIM, and DMARC results
• Look for pass, fail, softfail, or neutral statuses

Step 4: Review DMARC Reports

If DMARC is configured, review aggregate reports to see authentication failure rates and identify patterns.

How to Fix DNS Record Issues

General Fix Process

1. Identify the specific issue using DNS checker or email headers
2. Log into your DNS provider (where you manage your domain)
3. Locate the problematic record or add missing records
4. Update or add the record with correct syntax
5. Save changes and wait for DNS propagation (1-48 hours)
6. Re-check records to verify the fix worked
7. Test email delivery to confirm authentication passes

Getting Help

If you're unsure how to fix DNS issues:

• Contact your DNS provider's support
• Consult your email service provider's documentation
• Use MailMoxie's DNS Record Checker for specific recommendations
• Consider professional DNS configuration services

Prevention Best Practices

• Check records regularly: Quarterly audits catch issues early
• Test after changes: Always verify DNS changes work correctly
• Document your setup: Keep track of which services use which records
• Use DNS checker tools: Regular checks prevent problems
• Monitor DMARC reports: Reports show authentication issues
• Keep records updated: Remove old services, add new ones promptly

Common Questions

Q: How do I know if my DNS records have issues?

A: Use MailMoxie's DNS Record Checker to scan your domain. It will identify missing records, syntax errors, and configuration problems. You can also check email authentication headers in test messages.

Q: What's the most critical DNS record issue?

A: Missing SPF records are the most critical because they're the foundation of email authentication. Without SPF, emails are much more likely to be filtered as spam.

Q: Can DNS record issues be fixed immediately?

A: After fixing DNS records, you must wait for DNS propagation (1-48 hours) before changes take full effect. However, most changes are visible within a few hours.

Q: Will fixing DNS records improve deliverability immediately?

A: Once DNS propagates and records are correct, authentication should improve. However, if your domain reputation was damaged by previous issues, it may take time to rebuild trust.

Q: How often should I check my DNS records?

A: Check DNS records after making changes, when setting up new domains, when changing email providers, if you notice deliverability issues, and during quarterly maintenance.

Q: Can I have someone else fix my DNS records?

A: Yes, you can hire professionals or use services like MailMoxie's DNS configuration service to fix DNS record issues. Ensure you grant proper access to your DNS provider.

Key Takeaways

• Missing, incorrect, or misconfigured DNS records are a leading cause of deliverability issues
• Common problems include missing records, syntax errors, multiple SPF records, and domain misalignment
• Use DNS checker tools to identify issues quickly and get specific recommendations
• Fix issues through your DNS provider's dashboard and wait for propagation
• Regular DNS record checks and maintenance prevent problems before they impact deliverability
• Proper DNS configuration is essential for email authentication and inbox placement