Email deliverability checker
Live DNS checks for the four records that decide whether your mail lands in the inbox: SPF, DKIM, DMARC, and MX. Free, no signup — and if an AI agent sends email for you, these records are its reputation.
Build the records
Failed a check? Assemble a correct record here and paste it straight into your DNS.
@(domain root)TXTv=spf1 include:amazonses.com -allWhat gets checked
SPF — one TXT record at the root, valid syntax, and a strict -all/~all ending. DMARC — a policy at _dmarc.<domain>, graded on enforcement (p=reject or p=quarantine) and reporting (rua=). MX — the domain can receive replies, bounces, and reports. DKIM— a signing key at your selector, or the common selectors if you don't know it. Checks run live against public DNS; nothing is stored.
FAQ
What do SPF, DKIM, and DMARC actually do?
SPF lists which servers may send mail for your domain. DKIM cryptographically signs each message so receivers can verify it wasn't forged or altered. DMARC tells receivers what to do when a message fails both — and where to send reports. Gmail and Outlook increasingly junk or reject mail from domains missing them.
Why does this matter for AI agents?
An agent that sends email on your behalf lives or dies by your domain's reputation. One missing record means every message your agent sends starts in spam. If your domain sends through Hail, these records are provisioned for you — this checker is how you verify any domain, wherever it's hosted.
Why wasn't my DKIM key found?
DKIM keys live at <selector>._domainkey.<domain>, and the selector name is chosen by your sending provider. Without a selector we probe common ones (default, google, selector1, selector2, k1, s1, s2, amazonses). If your provider uses a custom selector, paste it into the selector field and re-run.
Is a warning a problem?
A warn means mail flows but something is weaker than it should be — like SPF ending in ?all (no enforcement) or DMARC at p=none (monitoring only). Fine while testing; fix before an agent sends real volume.
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