Antispam, Integration a new spam test that allows you to check the quality of your emails

Aleksandra Duło, 26 May 2021

The strict rules imposed by the providers make sending marketing emails not as easy as it seems. Why is it so challenging? Since some messages are non-compliant with best practices they can end up in the spam folder. Thus, many questions arise with regards to the creation itself, including how to prepare emails, how to authenticate them and how to format visuals, so the emails always appear in the main folder of the inbox. is the latest tool for testing emails trying to address the aforementioned issues. It is worth mentioning that it was created with the help of EmailLabs, which is a technological partner of this solution and has supported it with its knowledge and experience. allows you to easily rate emails from your browser while giving you tips on what to improve to ensure higher deliverability. Even though was created primarily with marketing emails in mind, it is also well suited for verifying other types of email, including transactional ones.

There are similar tools available on the market, yet focuses more on the technological aspects, giving access to much broader and more detailed analytics. Importantly, the solution is available for free with virtually no limitations. Even though is in its early days, there are two language versions available and it can be used on PC’s or mobiles. How does it work?

The Mailchecker .net interface has been designed to be user friendly, allowing a very smooth experience. After entering the website, a unique email address is automatically generated – send your email using this address and then click the Check output button. The result is rated from 0 to 100%. Bear in mind that a score below 90% suggests that the message can be classified as spam. Besides, provides detailed information about possible deficiencies, which allows users to quickly optimize all email parameters.

On the right side of the window, you can access the summary divided into main sections. A preview of the message is also available below allowing you to switch between the HTML view, headers, text, attachments and the original message.

In order to improve usability, each of the grading sections is marked in three colours. Green means full compliance with the requirements, yellow indicates some less important deficiencies, while red indicates critical problems that can have a real impact on email deliverability.

Along with just a description, MailChecker .net tells you exactly what needs to be done to fix the errors – just click the drop-down button to see all details of the vulnerabilities. What do we analyze?

Mailchecker .net analyzes various elements of marketing emails that affect deliverability, verifying all technical problems about the authentication, balance between images and text or RBL’s. Furthermore, it checks if the links and attachments are damaged or affected by the malware. In order to present the analysis clearly, it provides 5 main thematic sections, including headers, main body, ISP & DNS, antivirus and antiphishing, and blacklist.


This section allows the user to check headers for deliverability. verifies the correctness of SPF, DKIM, DMARC and SMIME. It also analyzes the IP of the message – its correctness is particularly important when using SMTP. It is also worth noting that incorporation of the headers such as -unsubscribe and Return-path lists also affects the overall rating.


The body section allows you to check if the text and URL of the message are properly structured. For this purpose, MailChecker .net provides an analysis of the sentences, the graphics to text ratio or the correctness of the HTML code. One must remember that the use of shortened links, iframe or JavaScript generated in the browser will significantly lower the final result.


In this section, MailChecker checks if the SMTP settings of your provider are correct and optimal. At the same time, your security is verified, so you can assess the level of your SPF, DKIM or DMARC.

Antivirus and Antiphishing

Thanks to this section you can check whether the message or attachments contain any malware. The tool also lets you know when the email resembles a phishing attack.


Thanks to this section you can access a list of the most popular blacklists (so-called RBLs). That allows you to check the status of whether the IP/domain from which you send the message is not listed on any of them. Remember to always have a clean account – otherwise, you should contact the RBL administrator for delisting. Further plans

Mailchecker .net is developed with the use of self-learning mechanisms.
Hence, we invite you to use the tool regularly, which will improve its effectiveness, available functions and the so-called user experience. Furthermore, you can expect new parameters as well as new language versions to be added in the coming days. For any further comments on please contact us a [email protected].

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