---
title: "Domain Health Checker | Refresh List"
description: "Review public MX, SPF, DMARC, and optional DKIM signals for a sending domain."
url: https://refreshlist.net/tools/email-sender-health-check
last_updated: 2026-09-25
---

[Refresh List](/) › Tools

# Email Sender Health Check

Use this working tool to inspect structure, plan credits, or query a domain without confusing that action with mailbox verification.

EVIDENCE-BASED DOMAIN CHECK Sending domain DKIM selector (optional) 

We check public DNS records only. We do not send email, probe a mailbox, or guarantee inbox placement. 

COMMON QUESTIONS 

## Domain health, answered.

What does the domain health score measure?+

It summarizes the DNS signals checked for your domain, including MX routing, SPF, DMARC, and optional DKIM. It is a configuration score, not an inbox-placement guarantee.

Does a high score guarantee delivery?+

No. Delivery also depends on sender reputation, message content, consent, recipient policy, engagement, and timing.

What is an SPF record?+

SPF lists the servers that are allowed to send mail for a domain. A published SPF policy helps receiving systems evaluate authorized senders.

What is DMARC?+

DMARC tells receiving systems how to handle messages that fail authentication alignment and where reporting can be sent.

What is DKIM?+

DKIM adds a cryptographic signature to outgoing mail. The checker can inspect a selector when you provide one.

Why is DKIM marked not checked?+

DKIM uses a selector chosen by your mail provider. Enter the selector, such as default or selector1, so the checker can inspect that specific record.

What does missing MX mean?+

It means the domain did not publish an explicit mail-exchange record in the lookup. This is a domain-routing signal, not proof that a specific address is invalid.

Can this tool check an individual mailbox?+

No. It checks public DNS records only and never probes a mailbox.

How current are the results?+

The result is a DNS snapshot at the time you run the check. DNS caches and record changes can affect what is returned.

What should I do after a Review result?+

Open the affected record in your DNS provider, compare it with your sending provider instructions, and re-run the check after propagation.

Does Refresh List store my domain?+

The checker sends the domain to a public DNS resolver for lookup and does not upload email lists or mailbox data.

## Sitemap

- [All Public Pages](https://refreshlist.net/sitemap.md)
- [Email Glossary](https://refreshlist.net/glossary)
- [Read This Page And Use Interactive Features](https://refreshlist.net/tools/email-sender-health-check)