Vladislav Podolyako
Jun 14, 2022
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You must have heard the combination “email deliverability” about a hundred times now. It’s a common term in online marketing circles. But for some reason, now, people also talk about testing their email deliverability. 🤔 So what’s all the fuss about? Why is email deliverability so vital? 

What does email deliverability mean?

First of all, email deliverability is a crucial part of any online business. Without it, you can’t go far–or, at least, you won’t be fruitful in your endeavors. Both the factor itself and testing email deliverability are an integral part of any decent business, which contributes to the overall success of your company, income, email traffic, and reputation. Otherwise, service providers will simply direct your messages to spam folders, and we don’t want that, do we?

But people often confuse email deliverability with its synonymous colleague, the delivery test. ❗️ The thing is, "deliverability" and "delivery" are two distinct terms. The former is a marketing word used to separate emails that have reached the recipient’s inbox from those that have not, whereas the latter is used to explain whether a recipient's server accepted a marketing message. 

The majority of email delivery problems are caused by technical problems, including a faulty connection or a mail server overload. The good news is that because mail servers immediately report delivery failures, email delivery tests are typically not essential. With email deliverability, though, things are different. Your rate will be low in case you have issues with such factors as bad content, not clean mailing lists, horrible sender reputation, and more. For this reason, you have to test your email deliverability once in a while

📃 We’ve got two pieces of news for you: a) yes, you must find out how to improve your email deliverability; b) it’s super easy to do once you’ve mastered the process and chosen the right email deliverability tools at hand. Keep reading to learn how to test email deliverability.

What impacts email deliverability?

So what affects email deliverability? Most marketers will tell you that a decent email deliverability score is around 95%, and they’re right. There are, in fact, multiple aspects that affect deliverability (aka the rate at which your emails get delivered). Here they are:

  • Server reputation: The receiving server's acceptance of your messages may depend on the service you employ to send your email marketing campaigns. Your mails might not make it through spam filters if you utilize a free service (like Gmail, Outlook, or Yahoo). We suggest going with a custom domain, which contains your company name.
  • Sender reputation: Your sender reputation is determined by how many emails you send, how many campaigns you run, how many users interact with your mailings, and how many of your marketing emails bounce. 🗑 If these criteria aren’t met, your emails go straight to the spam folder. Always keep in mind that any email service provider checks this factor before deciding how to regard your letters. 
  • Domain reputation: If you use a different address for your mailings than your campaigns, they are more likely to be delivered. Your business should ideally have a unique domain, and mailings should originate from a different email address. This way, any issues with customer billing are not a part of your marketing initiatives. 
  • Metrics for engagement: The majority of mail service providers give their clientele some sort of spam detection and email filtering service. Additionally, they might employ algorithms to ascertain how people respond to specific messaging. A provider might stop accepting emails from your domain if they discover that too many of your emails are being marked as spam, deleted without being viewed, or receive complaints.

Okay, this is pretty clear. But how do you know when to test email address deliverability? We have the answer.

When to test email deliverability?

There are several ways to determine whether or not it’s testing time. 💡 First of all, it’s a good idea to test your score before you launch a new email marketing campaign. This way, you can see what needs improvement and make the best out of your efforts. If you’re dealing with a long-term campaign, test every once in a while to stay up-to-date about your results.

Secondly, keep track of your score. A good email deliverability rate is somewhere around 80%, so if you are below this number, it’s time to test. If the rate is higher than 80% — congrats, you’re doing great!

Email deliverability testing tools

Now, it’s time for the fun part. While many business owners are terrified of testing email deliverability, there’s nothing to worry about. The process only seems hard at a first glance, but it’s a piece of cake — given you use effective specially designated tools. 🛠 Here are the best deliverability testing tools:


Folderly is a powerful all-in-one platform allowing you to perform a comprehensive email deliverability test and significantly improve your lead nurturing process. Not only does this tool conduct an in-depth analysis of the issues, but it also gives a wide variety of insights into the root cause of those problems. 


  • profound email deliverability test
  • cost-efficient solutions
  • domain reputation, IP address, and DNS settings analysis
  • precise sender score
  • excellent domain blacklist scanning
  • user-friendly spam prevention panel
  • powerful sender score protection
  • 0% email spam rate
  • 100% delivery rate


The paid version is quite expensive, but it is proportionate to the demands of an individual, startup, or agency.


Mail-tester is a popular tool helping you analyze emails once you send them to an individual account or specified address. It allows testing deliverability in just one step. The tool will tell you your potential spam score and how spam filters feel about your mails. The process is extremely easy: first, visit their website to copy the email address generated particularly for you, and then send an electronic letter to this address to see if it’s spammy. Blocklist checking and JSON API (only for paid plans though) are also on the list. Free users get three free tests a day.

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  • profound domain analysis
  • thorough spam check
  • authentication methods test
  • HTML code investigation
  • improvement suggestions


  • the tool sometimes applies outdated Real-time blackhole lists decreasing your sender score despite a perfect IP

MX Toolbox

MXToolbox provides innovative solutions for comprehensive server system analysis. It allows for monitoring and testing your campaigns. The tool takes care of SPF records analysis, as well as your headers, and outbound IP address email reputation. What’s in it for free users? Access to the top 30 blocklists with 1 free monitor.

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  • functionality reports on:
  • sender policy framework
  • domain-based message authentication, reporting & conformance
  • domainKeys identified mail
  • impersonation issues analysis
  • IP reputation check and alert
  • identification of senders’ geolocation


  • automatic one-year renewal
  • difficult to get early cancellation


With Mailtrap, you can put your messages to the test without disturbing your audience with this tool. It analyzes all the emails you send with the help of SpamAssassin, a potent anti-spam platform. It is also possible to test your campaigns in different environments with Mailtrap, including development and staging. 

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  • numerous inboxes
  • powerful email testing
  • message previews and forwarding
  • email redirecting
  • reviewing each message separately to inspect HTML issues deeply
  • comprehensive domain health checks


  • a limited number of emails in a free account

Sender Score

Sender Score allows for analyzing your reputation by making estimates based on a rolling 30-day average. It provides deep insights into how to improve your delivery rates, supporting them with solid data.

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  • convenient score system (from 0 to 100) for profound reputation analysis
  • IP address rank estimation
  • precise email deliverability rate calculation


  • Sender Score might miss on some factors that other tools would consider, but it still takes into account the essential ones


Unlike some tools mentioned above, Talos allows for a free reputation check. Doing research is quite simple with this service — the only thing you should do is enter your IP or domain name and wait for the results to appear on your screen.

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  • labeling web reputation as good, neutral, or poor (the last two characteristics indicate that your campaigns need improvement)
  • testing numerous email service providers
  • analyzing email volume
  • checking for blacklists


  • the tool doesn’t provide one-size-fits-all solutions; neither does it suggest profound insights into specific issues.


TrustedSource is a handy online tool that is run by McAfee, helping you check your website URL and come up with an alternative categorization. If your request does not surpass the boundaries of the norm, it is likely to be fulfilled in 3 to 5 business days. However, the process might take a bit more time if it requires specific knowledge.

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  • web reputation check
  • email domain reputation analysis
  • data on mail servers and DNS
  • deep insights into the domain’s activation and history
  • investigation of domain associations
  • website categorization check within the Webwasher URL Filter Database and SmartFilter Internet Database


  • you won’t get a reply to your request at the weekend
  • outdated ratings on the web

Microsoft SNDS

If you are eager to find out how your audience rates your emails, this tool will suit you perfectly well. Microsoft SDNS is one of the few mailbox providers that analyze sending reputation really deeply. Furthermore, this tool will help you check your IP address health. Microsoft SDNS sends an email to Outlook subscribers to provide the relevant data. 

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  • valid spam complaint rate
  • spam trap hits
  • spam filters test
  • comprehensive user response analysis
  • message reputation check


  • SNDS is considered outdated compared to other similar services


If you need an email deliverability test and a reliable spam checker, GlockApps will be the right tool for you. It is an all-in-one email deliverability tool that’ll do the job for you. It will detect spoofing, check email’s HTML code errors, monitor blocklists, you name it. It is ideal for campaign analysis, especially if messages are sent from different IP addresses. GlockApps allows you to investigate all aspects of your campaign and improve the results. Plus, it’s well integrated with MailChimp, which is why all MailChimp users love it. Any free features? Yes: 3 free reports and the ability to choose between plans.

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  • IP reputation checks
  • detailed deliverability analysis
  • real-time delivery reports
  • the tool is compatible with MailChimp, making the launches even easier
  • testing each seed list account separately
  • GlockApps Bounce Monitor feature allowing for finding bounced messages
  • authentication record tests (spam and sender score, DKIM, and SPF.)


  • the double opt-in confirmation becomes more challenging if you send over 70 emails

Google Postmaster Tools

Google Postmaster Tools is a perfect solution to numerous issues, supplying users with comprehensive data on various elements of your email campaigns. It allows for easy monitoring of different deliverability problems and offers great advice on fixing them. 

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  • encryption success rate
  • IP and domain reputation analysis
  • inspecting high-volume sending information
  • finding Gmail delivery errors
  • investigating DKIM/SPF/DMARC failures
  • spam complaint analysis


  • Google Postmaster Tools fail to always show correct reputation data
  • essential data are sometimes missing
  • the service often fails to provide updates
  • the service doesn’t always make official progress statements


Barracuda Central deals with Internet threats like no other tool. It provides its networks with the most recent data on the latest statistics, protecting them from potential dangers. The service is free and easy to use after quick registration. 

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  • unlimited blocking of spam emails
  • improved network security
  • state-of-the-art solutions to overcome Internet threats
  • quick malware detection
  • IP address reputation check
  • 95% spam accuracy rate


  • although Barracuda Central values honest feedback, it fails to provide its users with some essential features
  • no technical support
  • no landline service
  • database rules can be too strict, adding some innocent sites to the company’s blocklist
  • a high degree of automation may cause blocklisting of multiple email servers


SendForensics is an awesome tool for improvement since it compares your achievements with the ones of other businesses. You can get a complete report on the issues that need to be resolved. Furthermore, a paid subscription allows you to get even more crucial data, such as content analysis. You’ll also receive recommendations regarding inbox placement and online reputation.

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  • powerful email deliverability test
  • effective optimization strategies
  • tips on email content enhancement
  • email infrastructure improvement suggestions
  • preview option for popular email clients
  • impeccable reputation among popular senders all over the world


  • most features are available upon payment
  • lag time can sometimes be an issue
  • customer support managers usually respond within a few hours, but if they are busy, you might wait for several days to get a response

Spamcheck by Postmark

Spamcheck will provide you with an excellent email deliverability test. Even the free version is very easy to use, having a convenient interface and minimalist website design. Simply paste your HTML code into the search bar and see your score. The tool creates a comprehensive deliverability report. It will help you see if you’re dealing with any email deliverability issues and what service providers think about you. They also offer a free API, which allows you to automatically run spam checks on your letters.

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  • outstanding email deliverability testing
  • link checks
  • sender domain authentication
  • HTML quality checks
  • spam filter response analysis
  • suggestions on email improvement


The full version of Spamcheck is quite pricey

See how each tool stacks up

Here’s a technology comparison chart for you to see whether the tools you’ve chosen possess the crucial characteristics. 

Why test email deliverability in the first place?

Deliverability is of great significance to a marketing campaign's efficiency. Messages must get to the inboxes of the intended recipients and compel them to read them. Deliverability is important, so why? Email marketing activities are where businesses receive the greatest ROI. Therefore, more people will answer the marketer's call to action if more people read those campaign mailings, which ultimately leads to a greater sales rate. 💸


As you can tell, service providers will do everything in their power to protect their users’ inboxes from undesirable emails. That is why it is only logical for you to do your best to avoid having any characteristics that might potentially make you look bad in their eyes. 

This includes preventing any email delivery issues and, most importantly, deliverability problems. The good news is that the modern digital world is full of products to help you easily test any potential misfortunes and get ahead of your competitors. So go for it! The least you can do is try the free plan.

Vladislav Podolyako
Vladislav Podolyako
Founder & CEO
Vlad’s decades of entrepreneurial wisdom and business building experience have allowed him to successfully mentor a diverse group of business owners, entrepreneurs in growing their companies. A recognized expert in the areas of transforming organizational culture and leadership development, B2B Sales, Marketing, spent more than 10 years building technology products, with a background in communication networks and electronic device engineering.

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