Best Email Deliverability Tools: 9 Options to Improve Inbox Placement

It's not as simple as just pressing "send" to make sure your emails reach the inbox. Technical problems, errors in authentication, or a bad sender reputation can all cause even the best-planned campaign to fail. That's when email delivery tools come in. These systems let you see what's going on behind the scenes, which helps you find problems early and avoid the spam folder.

This guide shows you how to use nine of the most popular tools on the market right now. The goal isn't to pick a winner but to show you what each one has to offer, where it shines, and where it might not be enough so you can choose the best one for you.

What is an email deliverability tool?

In the simplest terms, email deliverability tools help you figure out if your emails are landing in inboxes or getting flagged along the way.

Most email service providers (ESPs), such as MailerLite or ActiveCampaign, already include a few built-in checks. They usually provide authentication setup, reputation basics, and some reporting. But those features are often quite limited.

Specialized deliverability platforms go deeper. They check:

• Whether your messages are being delivered to the primary inbox, promotions tab, or spam.

• If your authentication protocols (SPF, DKIM, DMARC) are properly configured.

• The health of your sending domain and IP reputation.

• Whether your list contains invalid or risky email addresses.

• How email filters and recipients might interact with your messages.

Depending on the size of your mailing list, your business type, and the stakes of your campaigns, you may decide that these additional insights are worth the investment.

Comparison of the 9 Best Deliverability Tools

Here are the tools we’ll look at in detail, along with the features they cover most

👉 Understanding and resolving most common delivery issues

Key Deliverability Features Explained

Before diving into each tool, it’s worth clarifying the main features deliverability software tends to offer:

• Inbox Placement: Shows where your emails end up (Primary inbox, Promotions, Spam).

• Spam Checker: Flags words, formatting, or structures that trigger spam filters.

• Authentication Checks: Confirms SPF, DKIM, and DMARC are configured properly.

• Reputation Monitoring: Tracks the status of your domain/IP against blacklists.

• Email Validation: Identifies invalid or fake email addresses in your list.

• Engagement Simulation: Mimics human actions like opening, clicking, or marking as “important” to strengthen sender reputation.

A Closer Look at Each Tool

1. Glock Apps

Designed with accessibility in mind, Glock Apps helps you see exactly where your messages land. With its seedlist testing, you can check inbox placement across providers like Gmail, Yahoo, or Outlook. It also runs spam checks and monitors your authentication setup and IP reputation.

Pros: Broad blacklist checks, detailed reports, and a few useful free tools.

Cons: Limited seedlist size means results should be viewed as indicators, not absolutes.

Pricing: Starts at $59/month, with a free plan offering 2 spam tests and DMARC monitoring.

2. Mailgun Optimize

Mailgun (part of Sinch) combines sending infrastructure with testing tools. Its Optimize suite lets you run inbox placement tests, monitor domain/IP reputation, and clean up your email lists with validation.

Pros: Integrates smoothly with Google Postmaster Tools and offers flexible APIs.

Cons: Geared more toward developers; inbox tests don’t distinguish between “Primary” and “Promotions.”

Pricing: From $49/month for the Pilot plan.

Read here : What Email Warmup tool is Better?

3. Mailtrap

Mailtrap is particularly developer-friendly, offering a safe sandbox environment to test emails before they go live. It checks spam scores, authentication, DNS, and blocklists, making it ideal for pre-send QA.

Pros: Strong for debugging, validation, and structure testing.

Cons: No inbox placement tests or engagement simulation.

Pricing: Free plan available; paid plans start at $14.99/month.

4. Unspam.email

This platform takes an all-in-one approach, combining spam testing, deliverability insights, and even AI-powered heatmaps to predict where readers’ eyes will go. It’s beginner-friendly yet detailed enough for advanced users.

Pros: Eye-tracking predictions, broken link detection, and device previews.

Cons: Seedlist smaller than some larger competitors.

Pricing: Free plan available; paid tiers start at $9/month.

5. Validity Everest

Built from the merger of Return Path, 250ok, and BriteVerify, Everest offers one of the broadest seedlists available. It provides competitive insights and advanced deliverability analytics, but comes at a higher price point.

Pros: Large global seedlist, detailed competitor insights.

Cons: Expensive, with features split across plans and add-ons.

Pricing: Starts at $20/month, but advanced plans go into the hundreds.

6. Warmy

Warmy specializes in email warm-up, gradually improving reputation by simulating engagement (opens, replies, marking as important). It’s ideal for new domains or IPs trying to establish trust with ISPs.

Pros: Offers customizable “warm up” settings and real-time chat support.

Cons: Small seedlist; heavy reliance on simulated activity.

Pricing: Starter plan begins at $49/mailbox/month

7. ZeroBounce

ZeroBounce packs nearly every deliverability feature into a single platform: validation, placement tests, blacklist monitoring, engagement simulation, and more. It also includes AI-based scoring and an email finder.

Pros: Comprehensive toolkit, many free features, 24/7 support.

Cons: Pricing structure can be confusing; verification can be slow on large lists.

Pricing: Plans from $18/month.

8. Folderly

Folderly positions itself as an automated deliverability assistant. It runs daily checks, warms up accounts, and engages with your emails to boost placement. For deeper reporting, its Inbox Insights add-on is required.

Pros: Automates daily upkeep; integrates with major ESPs.

Cons: Costs add up quickly; limited ISP coverage.

Pricing: Starts at $96/mailbox/month.

9. MxToolbox

MxToolbox goes beyond email, providing diagnostics for DNS and network performance as well. It’s particularly well-suited for IT teams managing large infrastructures.

Pros: Extensive monitoring, strong alert system.

Cons: Steep learning curve and higher pricing.

Pricing: Delivery Center plan at $129/month; free plan limited to blacklist checks.

Final Thoughts

Deliverability tools don’t guarantee perfect inbox placement, but they do give you the visibility and guidance to improve your chances. The right fit depends on your situation:

• For warming up new domains: Warmy or Folderly.

• For comprehensive, all-in-one monitoring: ZeroBounce or Validity Everest.

• For development and testing stages: Mailtrap.

• For IT-heavy teams: MxToolbox.

Whatever you choose, making deliverability a regular checkpoint in your email strategy ensures fewer surprises and more reliable campaign performance.