--- title: "Enterprise Email Deliverability, SPF/DKIM/DMARC & BIND DNS Auditor | GreenTree" url: https://www.greentreehosting.com/tools/email-deliverability-and-dns-sovereignty-auditor/ description: "Audit your domain’s SPF 10-lookup ceiling, 2048-bit DKIM signing, DMARC policy enforcement, and NS20/NS30/NS40 authoritative BIND zone alignment." format: text/markdown generated_from: prerendered HTML (build time) --- [All 4 Interactive Engineering Calculators](https://www.greentreehosting.com/tools) DNS & Mail Deliverability # Email Deliverability & Authoritative DNS Auditor. SPF, 2048-Bit DKIM, DMARC & Multi-Corridor Nameserver Verification. Evaluate your domain’s SPF 10-lookup ceiling, DKIM key strength, DMARC enforcement policy (`p=none` vs `p=quarantine` / `p=reject`), and nameserver geographic diversity. Since Google and Yahoo enforced **strict bulk-sender authentication requirements**, a single broken SPF include or missing rDNS/PTR record can route your company’s **invoices and proposals straight to spam**. [Web Application ROI Estimator](https://www.greentreehosting.com/tools/application-roi-and-architecture-estimator)[Cloud & Email TCO Calculator](https://www.greentreehosting.com/tools/cloud-and-enterprise-email-tco-calculator)[301 Cutover & SEO Validator](https://www.greentreehosting.com/tools/forensic-301-cutover-and-seo-equity-validator)[DNS & Mail Deliverability Auditor](https://www.greentreehosting.com/tools/email-deliverability-and-dns-sovereignty-auditor) ## Domain & Mail Authentication Parameters Corporate Domain Name SPF Record terminates with strict `-all` (Hard Fail) and ≤ 10 DNS lookups2048-bit RSA DKIM cryptographic signing active on outbound MTADecoupled MX Gateway (mail server does NOT share IP with public website)Multi-Node Authoritative BIND Nameservers (US East & US West Corridors) DMARC Policy Enforcement Level: AUTHENTICATION & DELIVERABILITY SCORE 96 / 100 ``` ; Authoritative 60s HA BIND Zone Blueprint for example-enterprise.com $ORIGIN example-enterprise.com. $TTL 60 @ IN NS ns20.greentreehosting.net. @ IN NS ns30.greentreehosting.net. @ IN NS ns40.greentreehosting.net. @ IN MX 10 mx.greentreemail.com. @ IN TXT "v=spf1 include:spf.greentreemail.com -all" _dmarc IN TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@example-enterprise.com; pct=100" ```