InboxMonitor and MXToolbox
Use MXToolbox when you want a one-time blacklist sweep across a very large set of lists, or the paid Delivery Center's inbox-placement tests, DMARC reports, and SPF flattening.
Use InboxMonitor when you want one domain's SPF, DKIM, DMARC, MX, PTR, and two named blocklists checked every day, with an email if the result gets worse.
Their site: mxtoolbox.com
Read on November 12, 2026.
Side by side
| Topic | MXToolbox | InboxMonitor |
|---|---|---|
| Blacklists checked | The public blacklist check tests a mail server IP against over 100 DNS-based email blacklists. The Delivery Center page also says MXToolbox checks 100+ blacklists. | PSBL and 0spam, for sending addresses the check can see. Spamhaus is not queried unless a paid key is set. A timeout or refusal is neither a listing nor a clean result. |
| How often | The public blacklist page is a lookup you run. Delivery Center's listed plans include blacklist monitoring, and the $129 a month plan names weekly blacklist monitoring. | Once a day. |
| Alerts | Delivery Center is sold as monitoring for blacklist, inbox placement, complaints, and mail flow. The public blacklist page itself is a lookup, not a saved daily watch. | Email when a daily check gets worse. Paid plans include a weekly digest. Slack is on Agency and Agency Pro. |
| Result page | A blacklist lookup result for an IP or domain you enter, plus Delivery Center tools for inbox placement, DMARC, SPF, DKIM, and complaints. | A domain page in the app: a 0–100 score, Healthy, Watch, or At risk, and the finding that changed the score. |
| Price | The Delivery Center page lists $129 a month (1 domain, weekly blacklist monitoring) and $399 a month (5 domains, 500,000 messages, 30 inbox-placement analyses a month, and other delivery tools). | Free is 3 domains, no card. Starter is $39 a month or $390 a year for 25 domains. Agency is $129 or $1,290 for 100. Agency Pro is $249 or $2,490 for 300. Paid plans include a 14-day trial with no card. Add a card before it ends to stay on the plan. InboxRescue Audit is $149 once for one domain. |
They do this, we do not
- The public checker covers over 100 blacklists. InboxMonitor queries two.
- Delivery Center includes inbox-placement analysis, recipient complaint reporting, DMARC performance reports, BIMI management, and SPF flattening.
- MXToolbox has offered email-delivery tools for a long time and states that more than 42,000 domains use them.
We do this, they do not
- A saved domain is checked every day without a separate monitoring product.
- The score is a fixed deduction from 100 for the findings on that run, with Healthy, Watch, and At risk labels.
- InboxRescue Audit writes the records for one domain. It does not promise placement or delisting.
Questions
Is InboxMonitor an MXToolbox alternative?
Only for a short, repeated authentication and blocklist watch. MXToolbox is the wider one-shot blacklist lookup, and Delivery Center adds placement tests and DMARC operations that InboxMonitor does not do.
Can I use both?
Yes. Use MXToolbox when you want the long blacklist sweep or a placement test. Use InboxMonitor when you want yesterday's DNS and the two named lists checked again tomorrow.
How is pricing different?
Delivery Center's page lists $129 a month and $399 a month. InboxMonitor Free is 3 domains with no card. Starter is $39 a month or $390 a year for 25 domains, with a 14-day trial that does not need a card.
Sources
- https://mxtoolbox.com/blacklists.aspxPublic blacklist check tests a mail server IP against over 100 DNS-based email blacklists.
- https://mxtoolbox.com/c/products/monitoring100+ blacklists checked; Delivery Center plans at $129 a month (weekly blacklist monitoring, 1 domain) and $399 a month (5 domains, 500,000 messages, 30 inbox-placement analyses a month); inbox placement, complaints, DMARC, SPF flattening, and BIMI are described on that page.