Introduction
No matter how polished your email campaigns are, they’re useless if they don’t land in the inbox. That’s where email deliverability monitoring tools come in. These platforms help you analyze, test, and monitor your email authentication, sender reputation, and inbox placement.
In this post, we’ll compare the top tools for monitoring email deliverability in 2025, including:
- ✅ MXToolbox
- ✅ GlockApps
- ✅ Mail-Tester
- ✅ Mailreach
- ✅ SendForensics
- ✅ Postmark
- ✅ Email on Acid
Let’s dive in.
1. MXToolbox
Website: mxtoolbox.com
Best for: DNS diagnostics, blacklist monitoring, and email server testing
Key Features:
- SPF, DKIM, and DMARC record checks
- SMTP server diagnostics
- Blacklist monitoring with alerts
- MX, DNS, and port tests
Pros:
- ✅ Fast, reliable diagnostics
- ✅ Free plan available
- ✅ Real-time blacklist alerts
Cons:
- ❌ No inbox placement testing
- ❌ UI feels dated
Pricing: Free & Paid (starting $129/year)
2. GlockApps
Website: glockapps.com
Best for: Inbox placement and spam filter testing
Key Features:
- Inbox placement testing across Gmail, Outlook, Yahoo, etc.
- Spam filter scoring
- DMARC analytics and authentication tests
- Blacklist and domain reputation monitoring
Pros:
- ✅ Most detailed inbox testing
- ✅ Great UI and dashboard
- ✅ Domain and IP reputation tracking
Cons:
- ❌ Paid only (limited free access)
- ❌ Seed list setup needed for full testing
Pricing: Starts at $59/month
3. Mail-Tester
Website: mail-tester.com
Best for: Quick, free deliverability checks
Key Features:
- SPF, DKIM, DMARC evaluation
- SpamAssassin scoring
- Blacklist and DNS check
Pros:
- ✅ Free and easy to use
- ✅ Beginner-friendly
- ✅ No login needed
Cons:
- ❌ No inbox testing
- ❌ Very basic reporting
Pricing: Free
4. Mailreach
Website: mailreach.co
Best for: Cold emailers and outreach teams
Key Features:
- Email warm-up automation
- Deliverability score and trend tracking
- Inbox, spam, and bounce analytics
Pros:
- ✅ Specialized for cold outreach
- ✅ Good warm-up automation
- ✅ Clear email health reports
Cons:
- ❌ No in-depth content analysis
- ❌ Setup required for each mailbox
Pricing: Starts at $25/month per inbox
5. SendForensics
Website: sendforensics.com
Best for: Technical analysis and predictive deliverability scoring
Key Features:
- Deliverability and quality scoring
- Spam filter analysis
- ESP integration and benchmarking
Pros:
- ✅ Powerful technical insights
- ✅ Predictive scoring engine
- ✅ Advanced reporting
Cons:
- ❌ Not beginner-friendly
- ❌ Pricier for smaller users
Pricing: From $49/month
6. Postmark Spam Check
Website: postmarkapp.com
Best for: Developers monitoring transactional emails
Key Features:
- SpamAssassin scoring
- Email content preview
- Fast, developer-focused interface
Pros:
- ✅ Fast and simple
- ✅ Developer-friendly
- ✅ Free
Cons:
- ❌ Limited to spam scoring
- ❌ No inbox placement analytics
Pricing: Free
7. Email on Acid
Website: emailonacid.com
Best for: Visual QA + inbox testing for email teams
Key Features:
- Email rendering on 90+ clients/devices
- Inbox placement testing
- Spam filter and pre-send testing
- Email QA workflow for teams
Pros:
- ✅ Great for design + deliverability
- ✅ Supports large email teams
Cons:
- ❌ Expensive for small senders
- ❌ Can be too advanced for simple needs
Pricing: Starts at $86/month
Comparison Table
| Tool | Free Plan | Inbox Testing | SPF/DKIM/DMARC Check | Best For |
|---|---|---|---|---|
| MXToolbox | ✅ | ❌ | ✅ | DNS & Blacklist Checks |
| GlockApps | ❌ | ✅ | ✅ | Inbox Placement Testing |
| Mail-Tester | ✅ | ❌ | ✅ | Quick Spam Testing |
| Mailreach | ❌ | ✅ | ✅ | Cold Email Outreach |
| SendForensics | ❌ | ✅ | ✅ | Technical Audits |
| Postmark | ✅ | ❌ | ✅ | Transactional Email Devs |
| Email on Acid | ❌ | ✅ | ✅ | Email QA & Rendering |
Final Thoughts
Deliverability is everything in email marketing. Whether you’re a cold outreach expert, a marketing team, or a developer managing transactional email — there’s a tool made for you.
Choose the one that fits your needs, test regularly, and stay out of spam folders in 2025!
