How to Check Email Deliverability for a Domain
Deliverability is more than one check. MX, SPF, DKIM, DMARC, and blacklist status each break it in a different way. Here is how to read all five, and a free scan that runs them together.
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"Why is my mail going to spam?" almost never has a single answer. Deliverability is a stack of independent checks, and any one of them can quietly sink you while the rest look fine. Checking deliverability means reading all of them and finding the weak link.
The five signals
1. MX records. Can the domain receive mail at all? No MX usually means a parked or dead domain. This is also the first thing a recipient's server confirms about you when you send. (See how to check MX records.)
2. SPF. Does the domain authorize the servers that send its mail? A missing record, a second record, or blowing past the 10-lookup limit causes soft fails that push you toward spam. (See how to check your SPF record.)
3. DKIM. Is outgoing mail cryptographically signed so receivers can trust it was not altered? A revoked or missing key removes a major trust signal.
4. DMARC. When SPF or DKIM fail, what does the domain tell receivers to do? A policy stuck on none means spoofers can impersonate you, which damages the domain's reputation over time. (See how to check a DMARC record.)
5. Blacklists. Is the domain or its sending IP listed on a DNSBL? Even perfect authentication will not save you if a major blocklist has flagged you.
Deliverability fails at the weakest link. Perfect SPF and DKIM do nothing if your IP is blacklisted, and a clean IP does nothing if DMARC lets anyone spoof you. You have to read all five.
Reading the result
Run them together and the picture usually points at one culprit: a domain that authenticates perfectly but sits on a blacklist has a reputation problem, not a configuration problem. A domain with great IP reputation but a p=none DMARC has an enforcement gap that will erode over time. The value of checking everything at once is seeing which layer is actually broken instead of guessing.
How to check it
The free deliverability scan runs MX, SPF, DKIM, DMARC, and a blacklist check in one pass and shows you each result with the raw record or reply behind it, so you can see exactly where the problem is. It does not save the domain you check.
To go deeper on any single layer, use the individual tools: SPF checker, DKIM checker, DMARC checker, MX lookup, and blacklist monitor. For the sending side, read how to reduce your email bounce rate.
Start with 500 free validation credits. No credit card.
Both Free and Pro run the same scan engine — full SMTP probe, MX lookup, typo, disposable, domain checks, and the evidence chain on every verdict. The difference is the monthly credit pool (Free=500, Pro=100,000) plus Pro's API and MCP access.