What Is a DNS & Email Security Checker?
DNS (Domain Name System) is the phonebook of the internet. A DNS checker queries global servers to see exactly what records are publicly attached to your domain name.
While DNS checks are common for verifying web hosting (A records), they are absolutely critical for email security. Without proper SPF and DMARC TXT records, your launch newsletters will go straight to spam, and attackers can easily impersonate you to scam your early users.
Understanding the 4 Key DNS Records
🌍 A & AAAA Records (Hosting)
These records point your domain name to an IP address. 'A' records use IPv4, and 'AAAA' records use IPv6. When someone types your domain into a browser, these records tell the browser which server to connect to.
📨 MX Records (Receiving Email)
Mail Exchange (MX) records tell the internet where to deliver emails sent to your domain. For example, if you use Google Workspace, your MX records will point to Google's servers. If this array is empty, your domain cannot receive emails.
🛡️ SPF Records (Sending Email)
SPF (Sender Policy Framework) is a TXT record starting with v=spf1. It acts as a guest list for your domain, telling the world which IP addresses and services (like Resend, Mailchimp, or Gmail) are authorized to send emails from your domain. If an unauthorized server tries to send an email as you, receiving servers will flag it as spam.
👮 DMARC Policy (Spoof Protection)
DMARC is a TXT record placed at the _dmarc subdomain. It tells email providers what to do if an email fails the SPF check. Setting p=none just monitors failures, while p=quarantine or p=reject actively blocks attackers from successfully spoofing your domain.
Frequently Asked Questions
What is an SPF record?
SPF (Sender Policy Framework) is a DNS TXT record that lists the IP addresses and servers allowed to send emails on behalf of your domain. Without it, your emails will likely go to spam, and attackers can spoof your email address.
Why do I need a DMARC policy?
DMARC works with SPF and DKIM to tell email providers (like Gmail) what to do if an email fails authentication. Setting a policy of 'quarantine' or 'reject' strictly prevents attackers from sending phishing emails as you.
What are MX records?
MX (Mail Exchange) records specify the mail server responsible for accepting email messages on behalf of a domain. If you do not have MX records, you cannot receive emails.
Why is the DNS checker returning different IP addresses than my host?
If your domain is behind a proxy like Cloudflare or a CDN like Vercel, the A and AAAA records will point to their edge nodes, not your origin server's direct IP. This is normal and expected for modern hosting.