Mail Check

Audit a domain's mail configuration: MX records, SPF alignment, DKIM selector presence, DMARC policy. Catch common deliverability issues in seconds.

Optional DKIM selector:

About mail check

Mail deliverability depends on three DNS records: MX (where mail is accepted), SPF (which servers may send on your behalf) and DMARC (what to do when SPF or DKIM fails). Mail check pulls all three plus DKIM (if a selector is known) and shows them together so you can see at a glance whether the domain is correctly configured.

What we check

MX records with priority, hostname, resolved IP, ASN and organization.
SPF TXT record. Missing ~all or -all at the end is a common deliverability issue.
DMARC TXT record at _dmarc.domain with policy (none, quarantine, reject).
DKIM at selector._domainkey.domain if you provide a selector (e.g. google for Google Workspace, selector1/selector2 for Microsoft 365).

Questions

What selector should I use?

Common selectors: google (Google Workspace), selector1 and selector2 (Microsoft 365), k1 (Mailgun), mandrill (Mailchimp), mxvault. If your DKIM is set up by a provider, check their docs.

Why is SPF ~all better than -all?

-all is a hard fail, ~all a soft fail. Most modern receivers treat them similarly when DMARC is also present. For new setups use ~all until DMARC reports look clean.

Does the tool query my mail server?

No. Only DNS records are queried (over DoH). No SMTP connection is made to your servers.

DNS Lookup

Query A, AAAA, MX, TXT, NS, SOA, CNAME, CAA and SRV records from authoritative resolvers.

IP Lookup

Instant geolocation, ISP, ASN, abuse history and reputation for any IPv4 or IPv6 address.

WHOIS Lookup

Domain ownership, registrar, nameservers and key dates.

Subdomain Finder

Enumerate subdomains via Certificate Transparency and OTX.