# Free domain monitor and email domain health checker

Check sender-domain health across SPF, DMARC, enforcement, and MX posture.

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Free domain monitor

Run SPF, DMARC, enforcement, and MX posture checks for any sending domain. Use the free check for fast diagnostics, then move critical domains into scheduled monitoring with history and alerts.

Run a free check

## Check a sender domain before the next release or send

Enter the domain used for product email, lifecycle messaging, or campaign traffic. The check scores sender posture and highlights issues that can affect inbox placement.

### See SPF, DMARC, enforcement, and MX posture together

The free check returns one sender-domain score plus specific pass/fail signals. Use it before provider migrations, lifecycle campaigns, product launches, and deliverability incident reviews.

- SPF authorized sender posture
- DMARC policy presence and validity
- DMARC enforcement posture
- MX inbound routing posture

## Key details

Primary use

### Sender-domain health

Check the sender DNS posture that affects product email, lifecycle messages, and campaigns.

Signals

### SPF, DMARC, MX

Review authentication, enforcement, and routing posture in one diagnostic view.

Best time

### Before launch

Run the check before provider migrations, campaign sends, and deliverability reviews.

## What this helps you evaluate

SPF

### Validate authorized sender posture

Check whether the domain publishes SPF information that supports the services sending mail on its behalf.

DMARC

### Review policy and enforcement

Confirm whether DMARC is present and whether the domain is still in observation mode or enforcing a stronger policy.

MX

### Check mail routing posture

Review MX state after provider changes, domain moves, and DNS updates so routing changes do not surprise support or operations.

## Related tools

### SPF checker

Validate authorized sender posture for a domain.

[Open tool](https://www.mailslurp.com/tools/spf-checker/)

### DMARC checker

Review DMARC policy, alignment, and reporting setup.

[Open tool](https://www.mailslurp.com/tools/dmarc-domain-lookup/)

### MX checker

Check inbound mail routing and MX priority.

[Open tool](https://www.mailslurp.com/tools/mx-record-check/)