Email deliverability tool comparison
Optimail vs MXToolbox
Last verified: April 2026. Pricing and features sourced from mxtoolbox.com.
Pricing at a Glance
| Tier | Optimail | MXToolbox |
|---|---|---|
| Free | $0/mo - 3 seed credits, basic dashboard | $0 - extensive free DNS/email lookup tools |
| Paid (mid) | Pro $49/mo - ESP integrations, Postmaster, SNDS | - |
| Paid (advanced) | AI+ $99/mo - AI recommendations, predictive forecasting | Delivery Center $129/mo - inbox testing, 5 domains, 500K volume |
Feature Comparison
| Feature | Optimail | MXToolbox |
|---|---|---|
| Seed / Inbox Placement Testing | ✅ | ✅ |
| AI Content Analysis & Recommendations | ✅ | ❌ |
| Google Postmaster Integration | ✅ | ✅ |
| Microsoft SNDS Integration | ✅ | ✅ |
| Blacklist Monitoring | ✅ | ✅ |
| DMARC Reporting | ✅ | ✅ |
| Free DNS/Email Lookup Tools | ✅ | ✅ |
| Email Header Analyzer | ✅ | ✅ |
| SPF Flattening | ❌ | ✅ |
| Domain Impersonation Protection | ❌ | ✅ |
| Klaviyo Integration (Native) | ✅ | ❌ |
| HubSpot Integration (Native) | ✅ | ❌ |
| Campaign-Level Analytics from ESPs | ✅ | ❌ |
| Deliverability Scoring Dashboard | ✅ | ❌ |
| IP Auto-Delisting | ✅ | ❌ |
| Free Plan | ✅ | ✅ |
| API Access | ✅ | ✅ |
Key Differences
MXToolbox and Optimail have more overlap than you might expect. MXToolbox has evolved beyond being just a DNS diagnostic tool. Its Delivery Center product now includes inbox placement testing (for Gmail and Outlook), Google Postmaster Tools integration, Microsoft SNDS integration, blacklist monitoring across 100+ lists, and DMARC reporting. These are serious deliverability features.
That said, Optimail and MXToolbox still serve different primary use cases. MXToolbox's core strength is its extensive free DNS and email diagnostic tools - MX lookups, blacklist checks, SPF/DKIM/DMARC validation, header analysis, SMTP diagnostics - which are the industry standard. These tools have massive brand recognition among IT administrators and DevOps teams.
Optimail's differentiators are AI-powered content analysis that explains why emails land in spam and provides specific fix suggestions, native Klaviyo and HubSpot integrations that pull campaign-level data into your deliverability dashboard, a deliverability scoring system, and automated IP delisting. These are capabilities MXToolbox does not offer.
MXToolbox offers SPF flattening and domain impersonation protection as premium features, which Optimail does not. MXToolbox also monitors 100+ blacklists and provides broader network diagnostic tools beyond email.
On pricing, Optimail Pro at $49/month includes ESP integrations and monitoring. MXToolbox Delivery Center at $129/month includes inbox placement testing for 5 domains and 500K email volume. Optimail AI+ at $99/month adds AI recommendations and predictive forecasting. Both offer substantial free tiers, but for different purposes: MXToolbox's free tier is individual DNS/email lookups, while Optimail's free tier includes seed test credits and a basic dashboard.
Where MXToolbox Shines
MXToolbox has the best free DNS and email diagnostic tools in the industry. For MX record lookups, blacklist checks, SPF/DKIM/DMARC validation, email header analysis, and SMTP diagnostics, MXToolbox is the tool email administrators reach for first. This is well-earned brand recognition built over many years.
MXToolbox's Delivery Center is more capable than many people realize. It includes inbox placement testing, Google Postmaster and Microsoft SNDS integration, complaint reporting, and mailflow monitoring. For teams that already trust MXToolbox, the Delivery Center extends that trust into deliverability monitoring.
Premium features like SPF flattening (which simplifies complex SPF records to stay within DNS lookup limits) and domain impersonation protection add genuine value for organizations managing complex email infrastructure. MXToolbox also monitors 100+ blacklists, which is among the broadest coverage available.
Who Should Choose Optimail?
Optimail is the right choice for email marketers, ecommerce teams, and agencies who use Klaviyo or HubSpot and want to understand the full deliverability picture beyond infrastructure diagnostics. If you want to know why emails land in spam (not just confirm that they do), need AI-powered fix suggestions, and want campaign-level ESP data correlated with inbox placement, Optimail provides capabilities that MXToolbox does not. Automated IP delisting and a deliverability scoring dashboard add further operational value.
Who Should Choose MXToolbox?
MXToolbox is an excellent choice for IT administrators, DevOps teams, and email infrastructure specialists who need reliable DNS diagnostics, broad blacklist monitoring, SPF flattening, and domain impersonation protection. Its Delivery Center is a solid option for teams that want inbox placement testing with Postmaster and SNDS data from a trusted brand. If your primary workflow revolves around DNS configuration and email server diagnostics, MXToolbox's depth and breadth of free tools are hard to beat. Many teams find value in using MXToolbox for infrastructure diagnostics alongside Optimail for campaign-level deliverability intelligence and AI recommendations.
Frequently Asked Questions
Is Optimail a replacement for MXToolbox?
Optimail complements what MXToolbox offers, but the two platforms have different strengths. MXToolbox has the best free DNS and email diagnostic tools in the industry, plus it now offers inbox placement testing and both Google Postmaster and Microsoft SNDS integrations. Optimail adds AI-powered content analysis, native Klaviyo and HubSpot integrations, campaign-level deliverability insights, and automated IP delisting. Many teams use both tools together.
Does Optimail offer free tools like MXToolbox?
Yes. Optimail offers free tools including a domain health check (SPF, DKIM, DMARC, MX audit), blacklist checker, email header analyzer, and SPF record generator, all available without signup. MXToolbox's free tools are broader in scope, covering MX lookups, DNS propagation, SMTP diagnostics, and more. Both platforms provide substantial free value.
Does MXToolbox offer inbox placement testing?
Yes. MXToolbox's Delivery Center ($129/month) includes inbox placement testing for Gmail and Outlook, along with complaint reporting, performance reports, blacklist monitoring, and mailflow monitoring for up to 5 domains and 500,000 email volume. It also integrates with Google Postmaster Tools and Microsoft SNDS.
Can I use Optimail and MXToolbox together?
Absolutely. Many teams use MXToolbox for its extensive free DNS lookup tools and ad-hoc diagnostics, and Optimail for ongoing AI-powered deliverability monitoring, ESP campaign insights, and actionable recommendations. The two tools complement each other well.
How does Optimail pricing compare to MXToolbox?
Both offer free tiers. MXToolbox's free tier is focused on individual DNS/email lookups. MXToolbox Delivery Center costs $129/month for inbox placement testing, SNDS, Postmaster, and monitoring for up to 5 domains. Optimail Pro starts at $49/month with ESP integrations and monitoring, while AI+ at $99/month adds AI recommendations. Optimail includes native ESP integrations and AI analysis that MXToolbox does not offer; MXToolbox includes SPF flattening and domain impersonation protection that Optimail does not.
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