Free Email Health Checker
Audit your domain's email deliverability and authentication health in real time. Inspect MX mail routing, validate SPF lookup limits, test DMARC enforcement policies, verify DKIM cryptographic keys, and ensure 2024+ Google & Yahoo bulk sender compliance.
The 5 Pillars of Domain Email Health & Deliverability
Email deliverability is no longer just about avoiding spam trigger words in your subject lines. In 2025 and 2026, major mailbox providers (Google, Yahoo, Microsoft 365, Apple) use automated machine-learning filters that evaluate your domain's DNS architecture before even opening your email payload.
To guarantee high inbox placement and protect your brand against spoofing, your domain must excel across all five foundational pillars:
1. Mail Exchangers (MX Records)
Inbound & DSNMX records direct incoming mail to your mail servers. Having at least two redundant MX servers ensures that even if your primary server experiences downtime, emails and delivery status notifications (DSNs / bounce reports) are safely queued by backup servers.
2. Sender Policy Framework (SPF)
RFC 7208SPF lists the authorized IP addresses permitted to send email on behalf of your domain. You must only publish one SPF record per domain, stay under the strict 10 DNS lookup limit, and end with ~all or -all.
3. DomainKeys Identified Mail (DKIM)
RFC 6376DKIM signs messages with an asymmetric cryptographic private key that receivers verify against your public key published in DNS. It proves that the message originated from you and was not altered in transit.
4. DMARC Policy Enforcement
RFC 7489DMARC ties SPF and DKIM together by enforcing domain alignment with the visible “From:” address. Transitioning from p=none to p=reject completely blocks scammers from spoofing your domain.
5. Brand Indicators for Message Identification (BIMI)
Inbox AvatarBIMI displays your official brand logo next to your emails in the Gmail and Apple Mail inbox, reinforcing consumer trust and improving open rates. BIMI requires DMARC enforcement (p=quarantine or p=reject).
Google & Yahoo 2024 Bulk Sender Mandates
Senders dispatching high volumes or commercial emails must comply with the following mandatory criteria:
- Authenticate both SPF and DKIM for the sending domain.
- Publish an active DMARC policy (
p=noneminimum). - Keep spam complaint rates in Google Postmaster Tools strictly below 0.10% (never exceed 0.30%).
- Include RFC 8058 one-click unsubscribe headers for all promotional and marketing communications.
Frequently Asked Questions
What does a score of 100 on Email Health Checker mean?▾
A score of 100 means your domain has redundant MX routing, an optimal SPF record under the 10-lookup limit, an enforced DMARC policy (p=reject), an active DKIM key, and a published BIMI record. You satisfy all major ISP inbox delivery standards.
Why does my SPF record have too many lookups?▾
Each include: mechanism in your SPF record triggers another DNS lookup, and nested includes count toward the total. If you use multiple tools (e.g. Google Workspace, Zendesk, Shopify, Mailchimp), their includes add up quickly. Consider SPF flattening or delegating subdomains for different sending streams.
How does EmailSendy help improve my domain's email health?▾
EmailSendy provides dedicated SMTP gateways with automated SPF and DKIM generation, managed IP warm-up, custom tracking domains, real-time bounce processing, and 1-on-1 deliverability infrastructure engineering.
Need 1-on-1 Deliverability Consulting?
EmailSendy deliverability engineers fix complex SPF lookup bottlenecks, resolve Microsoft 365 spam placement, and architect dedicated PowerMTA & Postfix clusters.
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