Email & Domain Auth Checker: MX, SPF, DKIM & DMARC
Email & domain checker for SPF, DKIM, DMARC and MX: DNS-only deliverability signals for lead lists and mail security audits, no SMTP.
How to pay
Pick whichever fits your workflow — you can switch any time.
Subscribe
$19/month
Predictable monthly cost with included usage. Best for steady, high-volume traffic.
- Unlimited tools within plan limits
- One API key, billed once a month
- Cancel any time
Pay-per-call
$0.01 per call
Charge agents in USDC the moment they call a tool. No subscriptions, no signup — pay only for what you use.
- 1 priced tool available
- Settled in USDC on Base
- No account or API key required
Email & Domain Auth Checker: MX, SPF, DKIM & DMARC
Check an email or domain's deliverability signals and email-authentication posture using only public DNS records. No SMTP connection, no mailbox ping.
What it does
This tool tells you whether a domain is set up correctly to receive and authenticate mail: MX records, SPF, DKIM, DMARC, plus disposable and role-address flags. It does not confirm a specific mailbox exists; that requires an SMTP handshake, a technique real mail providers throttle, block, or answer dishonestly often enough that it is less trustworthy than DNS signals, not more.
Who it's for
- Lead-list and signup hygiene: flag disposable and role addresses before they hit a CRM.
- Security and deliverability teams: audit a domain's SPF/DKIM/DMARC coverage before a sending campaign.
- Developers and AI agents: a DNS-based email/domain check as one step in a larger workflow.
Tools
- check_email_domain — Checks one email or domain's MX, SPF, DKIM, DMARC and disposable/role flags. Example input: input = user@example.com
- bulk_check_email_domain — Checks up to 100 emails or domains in one call, returning per-input results plus a summary.
Every result carries a status (OK, INVALID_INPUT, UNRESOLVABLE, NO_MX, or LOOKUP_ERROR), so you always know exactly what happened, never a generic failure.
FAQ
Is this email valid or deliverable? check_email_domain confirms the domain resolves, has real MX records, and ideally publishes SPF, DKIM and DMARC: the signals that determine whether mail is likely to arrive and be trusted. Does it check SPF, DKIM and DMARC? Yes, for every domain that resolves. SPF reports the "all" mechanism qualifier, DMARC reports the p= policy, and DKIM reports which of the checked selectors have a usable key. Does it detect disposable email addresses? Yes, against a bundled snapshot of well-known disposable and temporary-email domains. A "not disposable" result means "not on this known list," not a guarantee. Does it verify the mailbox? No, deliberately. There is no SMTP connection anywhere in this tool.
Trust & limits
Every check reads only public DNS records: no SMTP, no external paid API, nothing stored beyond the response. This is a deliverability-signal and auth-record check, not mailbox verification and not a delivery guarantee.