DNS Monitor vs MXToolbox
Comparing DNS Monitor and MXToolbox for DNS monitoring. Continuous monitoring vs on-demand diagnostic tools.
MXToolbox has been a staple of the DNS and email administrator's toolkit for years. It provides a comprehensive suite of diagnostic tools for checking DNS records, blacklist status, SMTP health, and email authentication. When something breaks, MXToolbox is often the first place people go to investigate.
DNS Monitor takes a different approach. Instead of waiting for you to run a check, it continuously monitors your DNS records and tells you when something changes. The distinction between on-demand diagnostics and continuous monitoring is the core difference between these two tools.
Feature Comparison
| Feature | DNS Monitor | MXToolbox |
|---|---|---|
| Continuous monitoring | ✓ | Paid plans only |
| On-demand DNS lookup | ✓ | ✓ |
| DNS change detection with diffs | ✓ | ✗ |
| Blacklist monitoring | ✗ | ✓ |
| SMTP diagnostics | ✗ | ✓ |
| Email header analysis | ✗ | ✓ |
| Propagation tracking | ✓ | Limited |
| All DNS record types | ✓ | ✓ |
| Change history and audit log | ✓ | Limited |
| SPF/DKIM/DMARC validation | ✓ | ✓ |
What MXToolbox Does Well
MXToolbox's strength is the breadth of its diagnostic capabilities. Their free tools cover a wide range of network and email diagnostics that go far beyond DNS:
Blacklist checking
MXToolbox checks your IP and domain against dozens of blacklists simultaneously. This is invaluable for email deliverability troubleshooting and something DNS Monitor does not do.
SMTP diagnostics
Their SMTP test tool connects to your mail server and walks through the SMTP handshake, reporting on each step. This helps diagnose email delivery issues at the server level.
Email header analysis
Paste in email headers and MXToolbox parses them into a readable format, showing hop timing, authentication results, and routing information.
Broad free toolset
The free tier includes DNS lookups, blacklist checks, SMTP tests, and more. For occasional diagnostic use, you may never need to pay.
MXToolbox excels at diagnostics
If you are troubleshooting an active email or DNS issue right now, MXToolbox's breadth of diagnostic tools is hard to beat. It is designed for reactive investigation, and it does that job well.
Where MXToolbox Falls Short
The core limitation of MXToolbox for DNS monitoring is that its free tools are reactive. You go to the website, type in a domain, and run a check. This works when you already suspect a problem but fails to catch issues you do not know about yet.
MXToolbox does offer paid monitoring plans, but their DNS monitoring is one feature within a broader email and network monitoring platform. The focus is split across many concerns rather than being deeply specialized in DNS change detection.
Reactive by default
Free MXToolbox tools require you to initiate each check. If an unauthorized DNS change happens at 2 AM, you will not know until you manually check or a user reports an issue.
Limited change detection
MXToolbox can tell you what a record is now, but it does not show you what it was before. There are no diff views comparing old and new values, and no timeline of changes.
Monitoring is not the primary product
MXToolbox's paid monitoring exists, but the platform is fundamentally a diagnostic toolkit. Monitoring is an add-on rather than the core architecture.
From Reactive to Proactive
DNS Monitor catches record changes before they cause incidents. Get alerts, diff views, and propagation tracking around the clock.
When to Choose MXToolbox
You need blacklist monitoring
If email deliverability is a primary concern and you need blacklist checks, MXToolbox's specialty in this area is a clear advantage.
You need SMTP and email diagnostics
For troubleshooting email delivery at the server level, MXToolbox's SMTP tools and header analyzer are purpose-built and effective.
You need occasional one-off lookups
For infrequent, manual DNS lookups during troubleshooting sessions, MXToolbox's free tools are convenient and comprehensive.
When to Choose DNS Monitor
You need continuous DNS monitoring
If catching unexpected DNS changes automatically is the priority, DNS Monitor's continuous watching and alerting is the right fit.
You need change history and diffs
Understanding what changed, when it changed, and what the previous value was requires a tool built around change tracking, not point-in-time lookups.
You manage DNS for many domains
Manually checking each domain with a web tool does not scale. DNS Monitor automates the process across your entire domain portfolio.
You need propagation monitoring
After making DNS changes, DNS Monitor tracks how those changes propagate across global resolvers, confirming the change took effect everywhere.
Using Both Together
MXToolbox and DNS Monitor work well as complementary tools. Use DNS Monitor for ongoing surveillance of your DNS records and instant alerts when something changes. When DNS Monitor flags an issue, use MXToolbox's diagnostic tools to investigate deeper, especially for email-related problems where blacklist checks and SMTP diagnostics provide context that a DNS monitor cannot.
Our Honest Take
MXToolbox is a genuinely useful tool that has helped administrators troubleshoot DNS and email issues for years. We recommend keeping it in your toolkit for diagnostics. But relying on a reactive diagnostic tool as your DNS monitoring strategy is like relying on a thermometer as your home heating system. It tells you the temperature, but it does not keep you warm. DNS Monitor provides the continuous, automated monitoring layer that turns DNS from something you check into something that watches itself.
The best DNS operations combine proactive monitoring to catch issues early with diagnostic tools to investigate when they arise.
Monitor DNS Continuously
DNS Monitor watches your records 24/7 and alerts you the moment something changes. Pair it with your favorite diagnostic tools for complete DNS visibility.
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