In most situations, skipping emails in inboxes or landing in spam mails have literary affected clients and mail users, leading to missing important pieces of information or even service disappointment. Poor email deliverability strategies or knowledge have negatively impacted business, with some losing their most important clients. There are numerous ways to improve your deliverability.

Top Email Deliverability Testing Tools

The main goal of this article is to teach and inform you on the next winning strategy and process for improving your mail deliverability experience by using email testing tools. In the article, we teach you the steps to test your email deliverability and the process to improve your email delivery. But first, a user must understand the conceptual terms "deliverability and delivery."

Deliverability vs Delivery

Mail users have always confused the real definitions of the terms email deliverability and delivery. For a common ground in understanding this article's contents, we must provide you with the conceptual definitions of email deliverability and email delivery. Email delivery simply refers to whether or not a receiver accepts your email. The process comes before inbox or spam folder distinction, meaning that an email is delivered to the correct email address and was accepted by a recipient's IP address. In cases where the message bounces for reasons like too heavy attachments, use of a non-existing domain, or incorrect email, the sender is notified almost immediately that the delivery has failed. When the message shows a positive result of being sent, it's seen as a success in the "Delivery Rate."

Sending reputation

Email deliverability is essentially a sender's ability to get their emails delivered to the right place in a recipient's inbox. It entails whether an email gets delivered into the spam folder or the recipient's inbox. This is the reason that makes deliverability to be also called "Inbox Placement." Improving email deliverability may seem simple, but it depends on numerous factors such as sender reputation, technical aspects and email contents. These are also factors that make automatic filters to determine where an email should go in the recipient's inbox. This article's primary focuses on explaining four excellent deliverability testing or measuring tools. The part of the Email Testing Checklist will also cover things that make email more deliverable, like content examination, sending test emails, and SMTP server testing. The four excellent deliverability testing tools are discussed as follows:

The first step to increasing email deliverability starts by running the email through an email checker. This allows you to attain the email deliverability ratio and determine the possible problems that might affect your mail from reaching the recipient's inbox. The article recommends an email checker through the homepage. platform is not loved by many for some little reason, but it forms the only viable start towards improving your deliverability. is a freemium tool that analyses specific emails and their content.

The sender initially uploads a mail in the pop-up recipient address displayed in the mail tester homepage to generate a score. Emails can also be tested using Email Sending Platforms like Sendinblue, BulkemailChecker, MailboxValidator or MailChimp. Test emails can also be sent to a specified address when previewing a campaign.

When using the testing tool, the email scores are generated within a few seconds. The mail tester is responsible for looking at the various factors affecting deliverability. It checks the likelihood of an email landing into spam and suggests ways of improvement. It reads the HTML message code after analysing the domain for the popular authentication domains to improve things. It finally checks if the mail was blacklisted by the recipient's domain, which may bring effects to the odds. This tester provides free and premium services for email testing to enable one to integrate it into an email app.'s premium pricing can be viewed here.

Spamcheck by Postmark

This is an email testing tool from Postmark, a popular email delivery provider. Postmark offers the best delivery rates, and this is their pride (see the postmark guide here). They offer an email deliverability testing tool for free. Using Spamcheck tends to be very simple since it involves pasting the HTML code of an email into a dialogue box together with the headers. Scores are shown within seconds whether it was better or lower. Comments showing email improvement ways are shown, and they address: the content quality links, the sender domain authentications, the ratio of text to image, and the HTML general quality. The reliability of SpamCheck is assumed because SpamAssassin is very popular for the assessment.

Postmark platform allows running spam checks automatically on the outgoing emails through its app integration features. Their API is free for the same purpose but also offers a wide library to enhance integrations with Python, Ruby, C# and others.


GlockApps enables users to analyse emails without necessarily registering. The results are always obtained instantly upon sending a mail to the platform mail displayed on the homepage. GlockApps emulates sending emails through Postfix and estimates the landing destination of an email. Another potential problem apart from spamming is when a well-formatted and written email is sent through Maligun; on most occasions, such emails tend to skip inboxes. The emails are missed because it mixes with the promotional emails. GlockApps' true power gets buried after registration within the complete reports. Sending emails to various domains between different countries makes one observe the performance. When using GlockApps, the client's reaction can be predicted when the massage exactly arrives.


The testing tool is known for email deliverability for detailed reports. One is always assigned an individual account to enable email sending when signing up. Emails can be sent right away after being assigned an account. An individual's results are compared with those of other people using the same company's services. SendForensics shows rankings and areas that need improvements. The platform's paid plan has numerous additional data, which improves content analysis. Other available options include email preview, inbox placements, and reputations.

Sender Score

Sender Score tool does not consider many factors like others discussed tools but is mainly concerned with the most critical factors. Essential data concerning the domain are seen on their homepage. The IP ratings can be seen when one signs up. Critical factors considered are the score during an assessment before the email is admitted. Building a good Sender Score takes several years. Their domain ratings are used when sending emails through ESP.

Mx Toolbox

It offers numerous tools for the improvement of the domain's capabilities. One of the tools is for validating a domain's authentication methods, which plays a significant role in email deliverability. Feedback is received within minutes after sending an email to

It ensures verification domain whether it is authentic and properly configured.


The tool strictly tests deliverables. Mailtrap enables one to set up an environment for capturing outgoing emails. Emails can be analysed using SpamAssassin. Behind every message, HTML is inspected to check what might cause problems to particular emails. It runs domains to deal with blockers. It works best in developing and staging environments. A copy of each email is sent to one's inbox even after the massage is well tested and taken to the user.

Other options worth considering

They are deliverability testing tools available; the best depends on one's opinion. Several of them can be combined to do testing. Various Email Sending Providers (ESP) offers numerous deliverability testing features. Some of these tools include Postmark, Sendinblue, and Mailgun. Their building is always done on their respective platforms. The tools act as a great supplement to the best tools for sending emails.

For top email testing performance use MailSlurp's free email testing tools.