DNS Authentication & Anti-Spoofing

Email Security (DMARC, SPF & DKIM)

Instantly test your domain protection against email spoofing and phishing attacks. Validate DMARC policy enforcement, SPF syntax, DKIM selectors, MX records, and BIMI.

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Frequently Asked Questions

Email Security & Deliverability FAQ

Why is configuring DMARC essential for my domain?
DMARC tells receiving mail servers (such as Gmail, Outlook, or Yahoo) how to handle emails claiming to be from your domain that fail SPF or DKIM checks. A strict policy (p=quarantine or p=reject) prevents attackers from sending fraudulent emails spoofing your brand.
What is the difference between SPF records and DKIM signatures?
SPF specifies via DNS which IP addresses and servers are authorized to send email on your domain’s behalf. DKIM adds a cryptographic signature to each email header to ensure the message was not altered in transit and confirms sender authenticity.
Why do my emails end up in the Spam folder?
Since 2024, providers like Google and Yahoo reject or spam-flag emails from domains lacking valid SPF and DMARC authentication. Furthermore, exceeding the 10 DNS lookup limit in SPF or having poor IP reputation drastically hurts deliverability.
What is the 10 DNS lookup limit in SPF?
RFC 7208 dictates that a mail receiver must not perform more than 10 DNS lookups when evaluating SPF (mechanisms like include, a, mx, redirect). Exceeding this limit causes a PermError, leading to rejected or discarded emails.
What is BIMI and how does it help?
BIMI (Brand Indicators for Message Identification) allows your verified brand logo to display directly beside your emails in recipient inboxes. It requires a strictly enforced DMARC policy (p=quarantine or p=reject).
How can I remediate email vulnerabilities for my company?
It is critical to adjust DNS records, implement DMARC with RUA/RUF reporting, and eliminate unauthorized relays. For comprehensive infrastructure evaluation, you can request a professional cybersecurity audit from our team.