MxToolbox
Free MX, SPF, DKIM and blacklist lookups, plus paid Delivery Center plans for DMARC reporting, inbox placement and blacklist monitoring.
From $129/mo Free tier API
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Bottom line
MxToolbox is the free DNS and blacklist lookup site most email admins already know, with paid Delivery Center plans for DMARC, inbox placement and blacklist monitoring. It suits agencies that want to check a domain setup fast for free and, at scale, monitor every sender on their domains. The free plan covers 1 domain, paid plans start at $129/month, and no free trial is stated.
Stands out for: Its free lookups need no account and check a sending IP against 100+ blacklists in seconds, which is quicker than signing up for a testing tool. Adaptive blacklist monitoring watches every third-party service sending as your domain, not only the IPs you list by hand.
Watch out for: The jump from free to $129/month is steep, and both paid plans cap you at 5 domains, which a cold email setup with many domains can outgrow. There is no warm-up and inbox placement covers only Google, Yahoo and Outlook.com.
Overview
MxToolbox has offered free email and DNS tools for over 20 years. Its homepage MX lookup queries the domain's authoritative name server directly, and diagnostics connect to the mail server to check reverse DNS, open relay and response time. The blacklist check runs a domain or IP against 100+ lists.
The paid product is Delivery Center. It parses DMARC reports to find legitimate, unknown and unauthorized senders, recommends SPF and DKIM changes as your senders change, and guides you safely to a reject policy to stop spoofing.
Delivery Center also includes inbox placement tests at Google, Yahoo and Outlook.com, complaint tracking from Google Postmaster and feedback loops, BIMI management and inbound and outbound mailflow monitoring. Delivery Center Plus adds SPF flattening to stay under the 10 lookup limit and tools for tracing who is spoofing your domain.
For a recruiting agency, the free tools are the everyday use: checking a new outreach domain's records after setup and confirming a mailbox has not landed on a blacklist when replies drop.
Who it's for
Best for
- Quick free checks of MX, SPF, DKIM and DMARC records
- Checking whether a sending IP or domain is blacklisted
- Teams moving a main domain to DMARC reject
- Agencies monitoring third-party senders on client domains
Not ideal for
- Cold email setups spread across more than 5 domains
- Anyone needing mailbox warm-up
- Small senders who want cheap paid monitoring
Key features
Free lookup tools. MX, SPF, DKIM, DMARC and DNS lookups plus a blacklist check against 100+ DNS based lists, with no account needed.
Adaptive blacklist monitoring. Finds every service sending as your domain from your DMARC reports, including ESPs and CRMs, and keeps watching them as their IPs change.
Inbox placement tests. Shows inbox, spam or rejected at Google, Yahoo and Outlook.com, with content analysis, header checks and tests against bulk sender rules.
DMARC reporting and enforcement. Parses aggregate and forensic reports from 500+ inbox providers and guides you from p=none to reject without blocking your own mail.
Complaint monitoring. Tracks your Google Postmaster spam rate against the 0.1% target and collects feedback loop complaints from Yahoo, Outlook.com and Mailgun.
Mailflow monitoring and API. Round-trip test messages every 5 minutes track delays, and a REST API runs lookups and queries monitors from your own systems.
Pricing
| Plan | Price | What you get |
|---|---|---|
| Free | $0/mo | Weekly blacklist monitoring, 1 domain |
| Delivery Center | $129/mo | 5 domains, 30 inbox placement tests a month, 500,000 messages |
| Delivery Center Plus | $399/mo | 100 inbox placement tests, 5,000,000 messages, SPF flattening |
| Managed Services | Custom | Hands-on setup and ongoing expert monitoring |
MxToolbox has a Free plan at $0/month with weekly blacklist monitoring of the top 30 lists for 1 domain. Delivery Center costs $129/month for 5 domains and 500,000 messages, with 30 inbox placement tests a month, DMARC reporting, complaint reporting, adaptive blacklist monitoring, mailflow monitoring, BIMI management and onboarding support. Delivery Center Plus costs $399/month and raises inbox placement tests to 100 a month and message volume to 5,000,000, and adds SPF flattening and advanced threat tools. Managed Services is custom priced and adds hands-on SPF, DKIM and DMARC setup and ongoing expert monitoring. The vendor does not state a free trial. Confirm current terms on the vendor site.
Checked 4 Nov 2026. Vendors change prices without notice.
Is MxToolbox expensive?
MxToolbox does not publish a price. It is one of 5 quote-based tools among the 53 deliverability tools in our directory. 10 have a free tier, and those with a public price typically start around $29 a month.
- 5 quote-based
- 10 free tier
- 50 public price
Worked out automatically from every deliverability listing, so it updates as the directory changes.
Pros and cons
Pros
- Free lookups with no account
- Blacklist check against 100+ lists
- REST API for lookups and monitors
Cons
- Paid plans start at $129/month
- 5 domain cap on both paid plans
- No warm-up or free trial stated
Integrations
Google Postmaster Tools Yahoo feedback loop Outlook.com feedback loop Mailgun
What's new at MxToolbox
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How MxToolbox compares
See all MxToolbox alternatives, with what each one does differently and a head to head for every pairing.
| Tool | Free tier | From | MCP | API | Compare |
|---|---|---|---|---|---|
| | ✓ | $129/mo | – | ✓ | |
| | – | $20/mo | – | – | Compare |
| | ✓ | $79/mo | – | – | Compare |
| | – | $15/mo | – | – | Compare |
$20/mo
MailReach adds warm-up alongside placement tests, which MxToolbox does not offer.
$79/mo Free tier
Folderly targets outbound sales teams with deliverability fixes, while MxToolbox centres on DNS, DMARC and blacklist monitoring.
$15/mo
Warmbox warms mailboxes for cold email, a gap MxToolbox leaves for a separate tool.
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