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Best tools to test email deliverability
Priya NainApr 21, 2022 12:33:01 PM8 min read

9 Best Tools to Test & Improve Your Email Deliverability

Billions of emails are exchanged daily, and over 100 million are blocked too from reaching the subscriber’s inbox.

With time, the ISPs are getting smarter and stricter in identifying potential spam. It’s good news since you’ll have fewer emails to fight for the subscriber’s attention. But that’s only possible if your email makes it to their inbox.

Since you can’t predict where your email will actually land, there are tools that can help you with this.

Here’s a list of 8 top tools that let you test and improve your email deliverability.

1. SendPost

SendPost can turn the manual hassles of your email journey into an effortless delight. It’s a powerful all-in-one tool that provides a complete package of email API services to developers, businesses, and ESPs.

It provides end-to-end support to deliver, measure, and optimize the email to ensure delivery to the subscriber’s inbox.

Key Features to Consider

  • Efficiency + Ease: SendPost provides API SDK in over 14 programming languages. It’s a godsend for all kinds of developers to use its features smoothly. And the integration is made super simple with ample help resources.
  • Smart Alerting: SendPost, by default, tracks the IP reputation and blacklist. And based on this data, it sends you instant alerts as soon as your email deliverability starts slipping below a threshold. It means you’ll never have to spend even a single minute manually fetching this data.
  • Dedicated IPs & Pools: You can manage both shared and dedicated IP pools. It also provides auto-warmup and advanced IP routing based on the receiver’s domain or email volume.
  • Validation API: You can use this straightforward API to clean your list of spam traps, hard bounce, email typos, or invalid email addresses. It also takes care of the sneaky scammers and phishers.


SendPost offers flexible pricing with its Starter, Growth, and Scale plan.

The Starter plan is priced at $7 per month, including 10k emails. The growth plan is $197 with 600k emails, and the Scale plan is $997 and includes 3M emails.

Who Should Use It?

SendPost is a perfect solution for developers, businesses of all sizes, and ESPs with millions of email traffic.

2. MxToolBox

With the correct authentication, half of your deliverability issues are resolved. MxToolBox focuses on precisely this.

It aims to boost your email deliverability with DMARC, DKIM, SPF, and real-time monitoring.

Key Features to Consider

  • Keeping Up With the Trends: Email deliverability is a constantly evolving field. That’s why staying updated with the latest information is crucial. MxToolBox has embedded emerging technologies like BIMI, Arc, and feedback loops.
  • Bulk Lookups: It’s handy when you need quick information on a vast data set.
  • Configurable Alerts & Historical Statistics: Each business can have its own definition of successful email deliverability. For such times, MxToolBox provides configurable alerts and gives you access to past data too for better analysis.


The free plan gives you one monitor and a weekly blacklist monitoring. The Delivery Center plan is priced at $129 per month with 64 monitors. And the Delivery Center Plus costs $399 per month and has 256 monitors.

Who Should Use It?

It’s an excellent option for enterprises and even freelancers running their own business single-handedly.

3. GlockApps

GlockApps ensures email deliverability for all major email service providers like Gmail, Outlook, Apple Mail, etc.

It focuses on spam tests and provides real-time reports that show whether your email landed in the subscriber’s inbox, spam, or wasn’t even delivered successfully.

Key Features to Consider

  • Uptime Monitor: You can get real-time notifications via email, Slack, or Telegram whenever the system encounters an issue with email deliverability. It makes tracking a piece of cake.
  • Template Editor: It highlights the ‘risky’ content in your email so that you can edit it to boost deliverability chances.
  • Automatic Inbox Test: It lets you test your emails with automated spam testing and sends a detailed report highlighting all aspects.


It has a free plan that allows one user to run 3 email spam tests. The paid plan varies between $59 to $249 per month. You can even create a custom plan for yourself with the help of their experts.

Who Should Use It?

The free plan can work for you if you use it for personal work. The paid plans are best for big enterprises with custom requirements.

4. SpamCheck

SpamCheck by Postmark is an online tool that analyzes your email content and scores you based on its deliverability probability.

You can paste your code directly onto the website. The system gives you a score on a scale of 0 to 5; the closer you’re to zero, the better it is.

Key Features to Consider

  • Simple Interface: It’s a straightforward tool that doesn’t need any manual to decode. You can use it from the get-go.
  • Suggests Revisions: Apart from scoring the content, it also highlights the changes you can make to improve the deliverability. It’ll check the quality of links, images, and HTML quality.


It’s a free tool, accessible to all through APIs as well. You can automate the spam scoring for all outgoing emails with API integration.

Who Should Use It?

Developers and small businesses can easily make the most of it through the quick public API integration.

5. Mailtrap

Mailtrap creates a sandbox environment to test the emails sent from the development phase. It tells you exactly where your email will land based on the recreation of the staging environment.

Key Features to Consider

  • Collaboration: It lets you share the staging environment with your team for the exchange of ideas.
  • Multiple Inbox: Since it’s a dummy inbox, you can replicate these to test different scenarios and confirm the email deliverability success.
  • Inspection: It allows you to debug your backend HTML code to see what might be bringing down the deliverability score.


It has a plan for everyone. Ranging from free to $299 per month, the features get added on with each plan.

Who Should Use It?

The email deliverability tool can easily appeal to all, whether it's a freelancer or a big enterprise. The plans are also affordable for long-term use.

6. Sender Score

Sender Score is an online service by Return Path. It rates your content on a scale of 0 to 100. It also lets you check the reputation of your IP address.

Key Features to Consider

  • Screening: Checks your IP to see if it’s part of any existing blocklist
  • Spam Monitoring: It evaluates the performance and gives you updates if people are marking you as spam or ESPs are blocking you.


It’s an entirely free tool.

Who Should You Use It?

Small businesses and freelancers can use it for basic yet effective analysis.

7. NeverBounce

Poorly curated or purchased lists often contain wrong email addresses, which can significantly impact your email deliverability.

NeverBounce cleans your bulky lists of invalid, wrong, and suspicious email addresses.

Key Features to Consider

  • Cross-platform Integrations: NeverBounce provides integrations with over 80 products that help you to create a seamless solution. It means you can verify the addresses right from the moment they are added to a CRM.
  • Instant Bounce Analysis: You can instantly get the report to view the performance regardless of your list size.
  • Free Deduplication: It removes the duplicate email addresses from your list without any extra cost.


The verification price per email ranges between $0.003 to $0.008, depending on your list size.

Who Should Use It?

If your email list is not organically built, you should try this to boost your email deliverability chances.

8. Mail Tester

Mail Tester is an affordable, simple, and effective tool to check the email list and score your email content.

It checks your email on all significant parameters to predict the deliverability accurately.

Key Features to Consider

  • Email Authentication: It checks your email for all primary and necessary authentication parameters like DKIM, DMARC, and SPF configuration.
  • Email Analysis: It analyzes your email content and images to score it on a scale of 1 to 10. The closer you are to 10, the better the email deliverability chances.
  • Blocklist Monitoring: It also monitors your email address for its reputation. If it’s in a blocklist, it will alert you.


Mail Tester is a free online tool.

Who Should Use It?

Small to medium businesses can use it to boost their email deliverability.

9. Folderly


Folderly is an all-in-one email deliverability platform that aims to locate, solve and prevent email deliverability issues. It helps businesses to build robust email infrastructure, increase email deliverability, get high open and reply rates, and boost outcomes through email marketing. 

Folderly provides you with scalable plans and ensures the guidance of an expert deliverability team. It offers solutions to various business needs, from email deliverability testing to complex domain audits. 

Key Features to Consider

Key Features to Consider

  • Variety of Solutions: Run inbox placement tests through the most popular email service providers, monitor your domain health, blacklists, and receive insights on IP information, DNS settings, and sender score.
  • Domain Reputation: Folderly provides you with automatically generated senders, which ensure an accelerated increase of sender score and mailbox security.
  • Seamless Integration: Folderly integrates with all popular email service providers and any custom providers via API and SMTP.
  • Email Template Analysis: Email template analysis dashboard allows you to create HTML or plain text emails and instantly check them for spam triggers.



    • Folderly offers you a Premium subscription, which costs $200/mo. It includes multiple features that make each of your emails land in the Inbox.

Who Should Use It?

Folderly is an excellent option for both email marketers and sales representatives to help them build their cold email outreach, and startups, small and medium-sized businesses, as well as enterprises. They all can benefit from Folderly solution and get their emails delivered to their inboxes.

Which Tool Should You Try?

There are many hacks and tips to improve your email deliverability. But, a suitable tool accelerates the process and reserves a space for you in the subscriber’s inbox.

After analyzing such great tools, you might be wondering where to place your bets.

To tackle this effectively, choose a tool that lets you get the most value without pulling your hair. A simple interface with maximum potential for customization can work brilliantly in the long run.

Considering this, you can definitely go ahead with a credible option like SendPost. Companies of all sizes are using it to send over 413 million emails with average deliverability of 99.23%. And the 24/7 dedicated support is a bonus.

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Priya Nain

A writer, content marketer, and editor with 4+ years of experience helping SaaS companies get users, and engage them. Nice girl, rarely mean.