Domain health checker
Check MX, SPF, and DMARC before email problems reach customers
Paste a domain or email address to inspect public mail DNS records. Use this to catch missing MX, weak SPF, or non-enforcing DMARC before you verify individual inboxes or import a list.
Check a domain
Paste a domain or email address to inspect public MX, SPF, and DMARC records.
This checks public DNS records. It does not verify a specific mailbox; use Verifly API checks for deliverability, disposable, role, catch-all, and mailbox signals.
Need mailbox-level verification?
DNS health only tells you whether a domain is configured for mail. Verifly checks individual addresses for deliverability, disposable domains, role accounts, catch-all behavior, and mailbox signals.
Start with free creditsThe four records that decide email health
This checker inspects the public DNS records that determine whether a domain can send and receive mail reliably. MX records point to the servers that accept inbound mail; without them, the domain cannot receive anything. SPF lists which servers may send on the domain's behalf. DKIM lets receivers cryptographically verify your mail, and DMARC tells them what to do when SPF or DKIM fail.
Reading all four together gives you a single snapshot of a domain's mail posture, from "fully protected and deliverable" to "wide open to spoofing."
Common problems this surfaces
The usual failures are missing MX (nothing to receive mail), an SPF record that is too permissive or exceeds the ten-lookup limit, a DKIM selector that no longer resolves, and a DMARC policy stuck at p=none so it monitors but never blocks. Any one of these quietly erodes deliverability or leaves the door open to spoofing.
Checking domain health before you verify individual mailboxes saves wasted effort: if a domain has no MX at all, every address on it is undeliverable regardless of format. For a per-record deep dive, use the dedicated SPF, DKIM, and DMARC checkers.
Domain health versus mailbox verification
Domain health is about the domain as a whole; verification is about a specific address. A domain can be in perfect health and still contain thousands of dead or invalid mailboxes. Conversely, a single valid-looking address on a broken domain will never deliver. You need both layers.
Use this tool to vet a domain before importing a list from it, then verify the individual addresses with the Verifly API at https://verifly.email/api/v1, whose GET /verify endpoint returns per-address disposable, role, catch-all, and SMTP flags.
Frequently asked questions
What does the domain health checker actually look at?
It reads a domain's public mail DNS: MX records for receiving mail, SPF for authorized senders, DKIM for message signing, and DMARC for the enforcement policy. Together these show whether the domain can send and receive mail reliably and how well it is protected from spoofing.
Why does a missing MX record matter so much?
MX records tell the world which servers accept mail for the domain. Without them, the domain cannot receive email at all, so every address on it is undeliverable no matter how well formatted. It is the first thing to fix before checking anything else.
Is a passing SPF record enough for good deliverability?
No. SPF is one of three authentication layers. You also want DKIM signing and an enforcing DMARC policy. Mailbox providers weigh all three when deciding inbox placement, and a domain with only SPF is easier to spoof and more likely to be filtered.
Does domain health tell me if a specific address is valid?
No. Domain health describes the domain as a whole. A healthy domain can still hold many dead mailboxes. To confirm a specific address exists you need mailbox-level verification, which probes the individual mailbox rather than the domain's DNS.
Should I check domain health before importing a list?
Yes. Vetting the sending or receiving domain first catches wholesale problems, like a domain with no MX, before you spend time and money verifying individual addresses that could never deliver anyway.
How do I check many domains and addresses at scale?
This tool checks one domain at a time. For bulk work, the Verifly API accepts a vf_ Bearer key and returns per-address deliverability signals, letting you combine domain-level and mailbox-level checks across a whole list.