Email deliverability test

What each check decides

MX — can the domain receive mail at all

No MX record means no address at the domain can receive anything. In practice a missing MX is usually a typo in the domain rather than a domain with no mail.

SPF — which servers may send as you

A DNS record listing authorised senders. The common faults are having none, having two (which is invalid and fails outright), and quietly exceeding the ten-DNS-lookup limit, which breaks the whole record rather than part of it.

DKIM — a signature proving the message was not altered

Keys live at selector-specific hostnames that cannot be enumerated from DNS, so this test probes the selectors the major providers use. A negative result means inconclusive, not absent — a custom selector will not be found.

DMARC — what receivers should do when the above fail

The policy is the entire point. p=none turns reporting on and blocks nothing, so a domain sitting on it is compliant with the 2024 Google and Yahoo requirement and still fully spoofable.

Blocklists — whether receivers are refusing you outright

A listing on a major list explains a sudden, total collapse in delivery better than anything else. Note that a check reported as unavailable means the list refused our query, not that you passed — we would rather say so than imply a result nobody verified.

Passing every check does not stop bounces

Worth being clear about, because the two problems get conflated constantly. Authentication records prove you are allowed to send as your domain. They say nothing whatsoever about whether the addresses you are sending to still exist.

A domain can score 100% here and still get throttled, because lists decay at roughly 2% a month and a bounce rate above about 2% is where mailbox providers start limiting you. Fix the records, then fix the list — in that order, since the records take minutes and the reputation damage from a bad send takes weeks to undo.

Common questions

How do I test my email deliverability?

Start with the records that decide whether receivers trust you: MX, SPF, DKIM and DMARC, plus whether your domain appears on a major blocklist. Enter a domain above and all five are checked in a few seconds. Every check is a DNS lookup, so nothing is sent to the domain and the test is invisible to it.

Why is my email going to spam?

In rough order of frequency: missing or misaligned authentication, a poor sending reputation from bounces and complaints, a blocklist listing, and low recipient engagement. This tool settles the first and third in seconds. Reputation and engagement are earned over weeks of sending behaviour and cannot be checked from DNS.

What is a good email deliverability score?

Treat anything below 100% as work to do, because each of these checks is pass or fail rather than a spectrum. The one people most often skip is DMARC: publishing p=none satisfies Google and Yahoo's bulk sender requirement while enforcing nothing at all, so a domain can look compliant and still be freely spoofable.

Does this test send an email to my domain?

No. Every check is a DNS query — MX, TXT and blocklist lookups. Nothing is transmitted to your mail server, nothing arrives in anyone's inbox, and the domain owner sees no trace of the test.

My records all pass but email still bounces. Why?

Authentication and bounces are unrelated problems. These records prove you are allowed to send as your domain; they say nothing about whether the addresses you are sending to exist. A hard bounce means that specific mailbox is gone, and the only fix is removing it before the send rather than discovering it afterwards.

Fix a failing record

Build a valid SPF record or DMARC record, or check one at a time with the SPF, DKIM and DMARC checkers.