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Free Email Authentication Tools

Check and generate SPF, DKIM, and DMARC records for your domain. Identify misconfigurations before they damage your sender reputation.

Used by outbound teams to validate DNS authentication before scaling campaigns

SPF Record Lookup

Check if your domain has a valid SPF record. See authorized sending servers and detect misconfigurations that cause authentication failures.

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SPF Record Generator

Generate a properly formatted SPF TXT record for your domain. Add authorized IPs, include third-party senders, and set your failure policy.

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DKIM Record Lookup

Verify your DKIM DNS record is published correctly. Check the public key, key type, and flags to ensure email signatures can be validated.

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DKIM Record Generator

Generate a DKIM TXT record with your public key. Configure the selector, key type, and flags for proper email signature verification.

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DMARC Record Lookup

Check your domain's DMARC policy. See the enforcement level, reporting addresses, and alignment settings that control unauthenticated email handling.

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DMARC Record Generator

Generate a DMARC TXT record with your preferred policy. Configure reporting, alignment mode, and percentage for gradual enforcement rollout.

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Why Email Authentication Matters for Deliverability

Email authentication is the foundation of inbox placement. Without properly configured SPF, DKIM, and DMARC records, receiving mail servers have no way to verify that your emails are legitimate. The result: messages land in spam, get rejected, or worse — your domain gets flagged as a spoofing source.

SPF

Authorizes which mail servers can send email on behalf of your domain. Prevents unauthorized servers from using your domain name.

DKIM

Adds a cryptographic signature to each email. Receiving servers verify the signature to confirm the message is authentic and unaltered.

DMARC

Tells receiving servers what to do when SPF or DKIM checks fail. Enables reporting so you can monitor authentication across all sending sources.

Since February 2024, Google and Yahoo require all bulk senders to have SPF, DKIM, and DMARC configured. Domains without proper authentication see significantly lower inbox placement rates and are more likely to be flagged by spam filters.

Need continuous monitoring?

These free tools check your records on demand. Superkabe monitors SPF, DKIM, and DMARC across all your sending domains automatically — every 24 hours — and alerts you before misconfigurations cause deliverability failures.

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Frequently Asked Questions

What are SPF, DKIM, and DMARC?▼
SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) are three DNS-based email authentication protocols. Together they verify that emails are sent from authorized servers, have not been tampered with, and define what happens when authentication fails. All three are required by Google and Yahoo for bulk senders since February 2024.
Why should I check my SPF, DKIM, and DMARC records?▼
Misconfigured or missing authentication records cause emails to land in spam or get rejected entirely. Checking your records identifies issues like exceeding the SPF 10-lookup limit, missing DKIM public keys, or weak DMARC policies before they impact deliverability.
Are these email tools free to use?▼
Yes, all Superkabe DNS lookup and generator tools are completely free with no signup required. You can check SPF, DKIM, and DMARC records and generate new ones as many times as needed.
How often should I check my email authentication records?▼
Check your records after any DNS change, email provider migration, or when adding a new sending service. For production sending domains, weekly checks catch drift before it causes deliverability problems.
What happens if my domain has no DMARC record?▼
Without a DMARC record, receiving servers have no policy for handling emails that fail SPF or DKIM checks. Spoofed emails using your domain may reach recipients unchallenged. Since February 2024, Google and Yahoo require at least a p=none DMARC record for all bulk senders.

Related Reading

SPF, DKIM & DMARC Setup Guide

Step-by-step DNS authentication setup for outbound email teams.

Complete Deliverability Guide

Everything you need to know about email deliverability and inbox placement.

How Spam Filters Work

Understand the mechanisms behind spam filtering and how authentication plays a role.