WHOISEmail Health Checker
A complete, scored overview of a domain's email configuration — everything in one place.
What is an email health checker?
An email health checker reviews the DNS settings a domain needs to send and receive email reliably, and turns them into one score out of 100. This one checks the mail servers, SPF, DMARC and the reverse DNS of the main mail server, explains each result, and shows the detailed findings for SPF, DMARC and MX underneath.
It is the quickest way to get an overall picture of a domain's email health before digging into any single record.
How the email health score works
Five checks each carry a weight. A check that cannot be evaluated is marked Unknown and left out of both the points earned and the points available, so it never lowers the score.
| Check | Weight |
|---|---|
| Valid MX records | 25 |
| Valid SPF record with no detected problems | 25 |
| A DMARC record exists | 20 |
| The DMARC record has no problems | 15 |
| First listed mail server has forward-confirmed reverse DNS | 15 |
The score is shown in green from 80, amber from 50 and red below 50.
How to run an email health check
- Enter the domain used in your email addresses, for example
example.com. - Press Check Email Health.
- Read the score and the five checks with their reasons.
- Scroll to the SPF, DMARC and MX sections for the detailed findings.
What the email health results mean
MX records
Passes when the domain has mail servers that resolve to IP addresses and do not point straight at an IP. A domain that publishes a null MX, which says it accepts no email, is marked Unknown rather than failed.
SPF and DMARC
SPF passes when exactly one valid record exists with no detected problems. DMARC is checked twice: once for the record existing, and once for problems such as a missing policy.
Forward-confirmed reverse DNS
The first mail server's IP address must have a PTR hostname that resolves back to the same IP. Many receiving servers check this, so a mismatch can hurt delivery. When a domain uses a hosted email provider, this check looks at the provider's server, which is normally set up correctly.
What this check does not include
DKIM is not part of the score, because it needs a selector name that cannot be discovered automatically; use the DKIM Checker with your selector. Block lists are not checked here either; use the Email Blacklist Checker with your mail server's IP address.
Fixing email problems in the right order
- Make sure MX records are correct, so mail can arrive at all.
- Fix SPF so there is exactly one valid record.
- Publish DMARC with a reporting address.
- Ask for reverse DNS on any mail server you run yourself.
- Set up DKIM with your provider and check it with the DKIM Checker.
- Raise DMARC to quarantine or reject once the reports look clean.
Common uses
- A quick review after moving to a new email provider.
- Finding the cause when customers say your emails go to spam.
- Checking a client's email setup before a newsletter launch.
- Re-checking records after adding a new service that sends mail for the domain.
Common problems and fixes
SPF fails. Look at the SPF section: the usual causes are two records or too many lookups.
No DMARC record. Add one at _dmarc, starting with p=none and a reporting address.
Reverse DNS fails. Ask the company that provides the mail server's IP address to set a PTR record matching the server's hostname. Hosted email providers handle this for you.
Related tools
- SPF Checker shows every SPF mechanism.
- DMARC Checker explains each DMARC setting.
- DKIM Checker checks the signing key the score leaves out.
- Email Blacklist Checker checks a mail server IP against block lists.
Frequently asked questions
What does the email health checker test?
Five things: whether the domain has valid MX records, whether it has a single valid SPF record, whether a DMARC record exists, whether that record has problems, and whether the main mail server has forward-confirmed reverse DNS. Each has a weight, and together they give a score out of 100.
Why is DKIM not included in the email health score?
DKIM keys are published under a selector name chosen by each email provider, and DNS offers no way to list them. Without the selector, the key cannot be found reliably, so it is left out rather than guessed. Use the DKIM Checker with your selector to check it.
What is forward-confirmed reverse DNS?
It means the mail server's IP address has a PTR record pointing to a hostname, and that hostname resolves back to the same IP. Receiving servers use it as a basic sign that a sending server is properly set up. Missing or mismatched reverse DNS can cause mail to be rejected or filtered.
What does Unknown mean in the results?
A check could not be evaluated, for example DMARC problems when there is no DMARC record, or reverse DNS when there is no resolvable mail server. Unknown checks are removed from the calculation, so the score reflects only the checks that could actually be run.
What is a good email health score?
A score of 80 or more, shown in green, means the core email records are in place and working. Between 50 and 79 there are gaps worth fixing, often DMARC or reverse DNS. Below 50, important parts such as MX or SPF need attention before email can be relied on.
Does a high score guarantee my emails reach the inbox?
No. The score covers the technical setup that receivers check first. Delivery also depends on your sending reputation, the content of messages, complaint rates and whether people engage with your mail. Good records are the foundation, not a guarantee, so keep lists clean and send mail people expect.
What is a null MX record?
A null MX is a single MX record with priority 0 and a target of a single dot, defined in RFC 7505. It tells senders the domain accepts no email at all. This checker treats it as a deliberate choice and marks the MX check as Unknown instead of failing it.