SPF, DKIM & DMARC Checker

How the SPF, DKIM & DMARC Checker Works

This tool queries your domain's DNS records to audit email authentication:

1. MX records, verifies your domain has mail exchange records pointing to email servers. Also detects your email provider (Google Workspace, Microsoft 365, Zoho, etc.).
2. SPF validation, checks for an SPF TXT record, validates the syntax, detects dangerous mechanisms like +all, and counts the DNS-lookup terms written directly in the record against the 10-lookup limit. It does not expand include: targets.
3. DKIM lookup, checks the exact selector you provide. Without one, it samples common selectors and labels the result as limited rather than proving DKIM is absent.
4. DMARC analysis, checks for a DMARC record, evaluates the policy (none/quarantine/reject), verifies report addresses (rua/ruf), and flags percentage restrictions.

Why Email Authentication Matters

Email authentication is no longer optional, it's required by major inbox providers:

• Provider requirements, major mailbox providers publish authentication requirements for senders, with additional DMARC and alignment rules for bulk traffic. Check each provider's current documentation for the thresholds that apply to your sending pattern.
• Spoofing and phishing protection, without SPF, DKIM, and DMARC, anyone can forge emails that appear to come from your domain. Phishing attacks using your domain damage brand reputation and customer trust.
• Inbox placement prerequisite, authentication is one input to provider filtering, alongside alignment, reputation, complaints, content, and recipient behavior. This DNS check measures none of those other factors.
• Domain reputation, email providers track domain reputation over time. Authentication establishes identity, while complaints, bounces, engagement, sending patterns, and content still influence filtering.
• Business email reliability, authentication reduces spoofing risk and supports delivery, but it cannot guarantee inbox placement for transactional messages, newsletters, or everyday correspondence.

After checking email authentication, verify your domain's DNS setup with our DNS Lookup tool and check your SSL certificate with the SSL Certificate Checker. Also run a security headers check to ensure your web server is hardened alongside your email setup. For full domain intelligence, the WHOIS Lookup shows domain registration, registrar, and expiry details.

How to Fix Email Authentication Issues

Common fixes for email deliverability problems:

• Missing SPF, add a TXT record to your DNS with v=spf1 include:_spf.google.com ~all (replace with your provider's include). Use ~all (soft fail) or -all (hard fail).
• Missing DKIM, enable DKIM signing in your email provider's settings. Google Workspace, Microsoft 365, and most providers offer one-click DKIM setup that adds the DNS record automatically.
• Missing DMARC, add a TXT record at _dmarc.yourdomain.com with v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com. Start with p=none to monitor, then upgrade to p=quarantine or p=reject.
• SPF +all, change +all to ~all or -all immediately. +all means anyone can send as your domain, defeating the purpose of SPF entirely.
• Multiple SPF records, merge into a single record. Having more than one SPF record causes authentication failures per RFC 7208.
• DMARC p=none, use aggregate reports to identify legitimate senders, align them, and move toward p=quarantine or p=reject only when the evidence shows the change will not block valid mail. A monitoring policy requests no receiver enforcement.

For help setting up email authentication and improving deliverability, explore our SEO services which include technical site audits covering email DNS configuration.