MailSlurp Blog

MailSlurp Blog

MailSlurp technical blog from the developers. Posts about email API testing and features added to the platform and new examples.

Office Puppy

Office Puppy Behold the MailSlurp office puppy Wusi. She is a chihuahau/mini-pinscher mix and she keeps everyone motivated. She is a big believer in email testing and epowering developers to do the best! Wusi’s wish Wusi has communicated that she want every QA tester, marketer, and developer to enjoy the email APIs available free of charge at MailSlurp. Try MailSlurp today.


The Recommended Email size

The Recommended Email size Do you know what the email attachment size limit is to the content you put in your email? Several, if not all, email sending service providers restrict how far the email attachment size should go. The limitations are put because of security reasons as well as performance. For this reason, when considering sending out email notifications or newsletters, you should consider the size of the file attachments and HTML.


The Difference between POP3 Vs. IMAP Emails

The Difference between POP3 Vs. IMAP Emails When it comes to retrieving email messages, you have to do it right. To regain your emails, you need to be intentional which the method you pick on doing so. There are basically two options to choose from, that is POP3 vs. IMAP. They do the same work but vary in so many ways from each other. Here is how POP3/POP POP is initial for Post Office Protocol.


SMTP Port Guide

SMTP Port Guide Everyone wants a successful delivery of their email. What stands between desire and real success is the correct port of transmission. You might think that it is not much of your problem because the service provider worries about that. Nevertheless, a default SMTP is no assurance of the best delivery. Therefore, it is essential to learn some other port alternatives that will better deliver your mail. What are SMTP and SMTP Ports and their roles SMTP is initials for Simple Mail Transfer Protocol.


What is an SMTP Server?

What is an SMTP Server? If you ask anyone whether they can send an email, a good percentage of them will answer in the affirmative. People do not realize that the behind-the-scenes of receiving and sending emails are a technical system. What assists you in sending mail is called a server. A server handles particular services; in this case, an email server deals with mails only. The email server division is into two, the outgoing and the incoming server.


NBSP in HTML emails

NBSP in HTML emails Of the easiest thing to use on the keyboard, it is the space bar. You can even do it while your eyes are closed. You press the big button at the bottom of your computer keyboard, and space appears. However, it is not as easy as it seems when it comes to HTML code. There are several ways to make the room appear in HTML, one of the ways is  .


What is DKIM Email

What is DKIM Email? Spam messages are not anyone’s favorite. However, to defend those companies, they send them to inform potential customers about their clients. Over time bots have changed how most people and companies send email marketing messages to you. With these bots, companies send emails while impersonating themselves as one of your friends or relatives. When this happens, you are likely to click on the links in the emails.


Email for testing

Email for testing One of the laborious things in QA professional life is testing email workflow. It involves a lot of sweat and labor. There are also the expectations of working with speed plus the possibility of something going wrong. For this reason, several developers have come up with random email generator dummies to assist you in avoiding the hassle. How do dummy emails works It is effortless to generate random emails.


DotNET Core Cake Task Runner (CSharp Makefiles for coverlet code coverage and more)

DotNET Core Cake Task Runner (CSharp Makefiles for coverlet code coverage and more)

DotNET Core Cake Task Runner (CSharp Makefiles for coverlet code coverage and more) Cake is a free open-source task runner for writing custom cross-platform builds stages for .NET applications. MailSlurp uses Cake to build CSharp SDKs for its free email API. In this tutorial we will show you how to create Cake files and a dotnet tool manifest in order to create custom builds and tasks in your .


CC and BCC in SMTP

CC and BCC in SMTP Numerous questions arise from people asking, what is Bcc in email, and how does it work? They also ask what is cc in an email and how it differs from Bcc. For this reason, here is a short compilation of information on cc and BCC and their role in SMTP (Simple Mail Transfer Protocol). How Cc and Bcc vary in emails Let’s take a look at both cc and bcc in emails.


How to use Mailto Links

How to use Mailto links If the phrase as old as the internet is correct, then the word as old as HTML is valid. HTML has been around for a very long time, and so has mailto. Which happens to be one of the most common schemes of HTML. Even with the evolution of the world, ol' mailto has remained relevant. Mailto functions very effortlessly. It is put behind a particular text.


Avoiding Spam Filters

Avoiding Spam Filters When sending emails for marketing, no one wants their emails to go to the spam folder. The target is to reach as many clients as you can. According to statistics, over time, the percentage of email messages getting to a recipient's inbox has increased. To be precise, five out of six commercial emails hit the targets. You do not want to be among the ones who miss the goal.


Hugo responsive image srcsets

Hugo responsive image srcsets

Hugo responsive image srcsets How to render picture tag images in Hugo with custom render-image.html layout. What is hugo? Hugo is a static site generator written in Go. One can write content in markdown and render HTML using simple HTML templates. What are responsive images? Responsive images are images on a website that differ based on screen size or device properties. One popular method in HTML5 to serve responsive images is the <picture> tag.


Random email generator

Random email generator

Random email generator Create random email accounts with MailSlurp’s free email API. Why do we need random emails? Randomized email accounts are useful for testing and privacy. MailSlurp is a free random email generator that can be used by anyone. Sign up and create an inbox You can sign up free and create real email addresses. These email addresses can send and receive real emails and attachments. Code or UI access Create random email addresses in the online dashboard or programmatically in a number of languages.


Receive email in code

Receive email in code

Receive email in code and tests MailSlurp is a free API for that lets your receive emails in test and code. How to receive emails in tests and event listeners Many applications today have the need to either send or receive emails. Perhaps your app needs to receive invoices from customers via email; or you want to test user sign-up processes with real email addresses. In each instance you need to somehow get SMTP mesages into memory from within a test or applicaiton.


Email API Send Attachments

Email API Send Attachments

Send attachments with an Email API Sending email attachments Even though attachments are an incredibly common aspect of email, SMTP, the underlying protocol, doesn’t actually specify what one is or how it should be transferred. Attachments weren’t really a thing when email was invented. However, the designers left room for extension with the concept of MIME Parts. SMTP MIME extension Attachments that your receive in Gmail or Outlook are actually transferred as ASCII text using an encoding called MIME.


Email API

Email API

Using Email APIs to send and receive emails MailSlurp is a free email API for creating email accounts on demand that can send and receive real emails from code or tests. What is an email API? Many applications and businesses today depend on email. Email powers user sign-up, invoicing, payments, communication and more. Email has been around for a long time but the underlying SMTP technology hasn’t changed much.


Deploy Redash to AWS with Terraform

Deploy Redash to AWS with Terraform

Deploy Redash to AWS with Terraform What is Redash? Redash is an open-source data visualization tool used by companies as diverse as Soundcloud, Mozilla, and Waze. It allows developers and analyts to query data, graph results, and share insights with others. The best thing about Redash is that it is completely free to self-host (minus your own infrastructure costs). Why deploy self-hosted Redash? Redash.io offers a super simple one-click start for hmanaged Redash instances.


NodeMailer NPM Tutorial

NodeMailer NPM Tutorial

NodeMailer NPM Tutorial NodeMailer is a popular NodeJS package for sending and receiving emails. It’s open source and has no external dependencies! Let’s see it in action: NodeMailer requires access to an SMTP server, if you don’t have access to one or need a frontend solution try MailSlurp’s email API Installing NodeMailer First create a new NodeJS project with npm init -y. Then install NodeMailer from NPM with npm install --save nodemailer.


Fake Email Generator

Fake Email Generator

Fake Email Generator What are fake email accounts It can be tiresome to sign-up for a new email account every time you want to test something. Email generators like MailSlurp let you create real email addresses instantly using a web app or developer tools. Receive emails to fake accounts MailSlurp inboxes using @mailslurp.com addresses or your own custom domain. Email API access You can generate fake email accounts programmatically using MailSlurp’s HTTP API or one of the many official SDK libraries.


Using test email accounts to test user sign up (using CypressJS)

Using test email accounts to test user sign up If you are a software developer you know how hard it can be to test user sign-up on websites or mobile apps. Many applications rely on unique email addresses. Additionally most user sign up processes rely on email verification. How do we test this in automated tests? Creating email addresses in code With MailSlurp (a free email API) you can create real email accounts on demand in code or tests.


Test user sign up with NodeJS and Jest (testing email verification codes)

Test user sign up with NodeJS and Jest (testing email verification codes) An example Let’s imagine we have an application that allows users to sign-up. When they do they are sent a confirmation code via email. They are then asked to enter that code to verify their account. How do we test this? Test email accounts Services like MailSlurp provide test email addresses that can be used via HTTP APIs. If we create a new email address during each test run we can sign up with its unique email address and then parse the confirmation code to verify the account.


Receiving emails in tests

Receive emails in tests Why we need emails in tests Many applications send emails. They may be sent when a user signs up, or as part of a monthly newsletter. Whatever the reason, emails are essential for many programmers. As most developers use transactional email services, testing applications end-to-end can hit a wall when emails enter the picture. For many use cases the need for real and unique email addresses arises.


How to send emails with MailJet

How to send emails with MailJet What is MailJet MailJet is a SAAS API for sending transactional emails. These emails are usually triggered by your application in response to a particular event. An example is sending an email to a new user when they sign-up. What does it solve? Services like MailJet make sending emails easy by abstracting SMTP protocols behind HTTP APIs, SDKs, and client libraries. This means you can concentrate on the emails you send not on how you send them.


What is transaction email (and how to send it)

What is a transactional email? Transactional emails are emails that are sent on behalf of an application as a result of a particular user event. Typically this can mean email verification messages, newsletters, invoices, and much more. Triggering emails Many applications have logic that handles user actions that should result in an email being sent. They then create an email and send it via SMTP or an email sending service.


Generate test email accounts

Test email account If you need unique random email addresses for any reason you probably want to use test email accounts. MailSlurp is a free service for creating real email accounts in code, tests, or using a dashboard UI. Create test email addresses You can generate test email accounts on demand with API services like MailSlurp. MailSlurp let’s you create real, random email addresses from code then send and receive real emails.


Generate email addresses for testing

Generate email addresses for testing

Test email accounts Why developers need real email addresses Sending and receiving emails is an important aspect of many applications. Testing these processes is often difficult. It may be that user sign-up requires a unique email address so end-to-end testing this process requires a new email address each time. Often developers will avoid testing these areas as they aren’t aware of services like MailSlurp. MailSlurp lets you generate email addresses to send or receive emails from during tests.


Transactional Email Services Compared

Transactional Email Services Compared Many applications need to send emails at some point or another: either for user confirmation, password reset, newsletters, support and more. Whatever the use-case, sending emails with a transactional email service removes the time and stress of configuring a custom SMTP server. Remember, it’s important to test your email sending functionality end-to-end. MailSlurp is a email test account generation API that lets you create random unique email addresses and then send and receive real emails with them.


Sending emails in Javascript (3 ways to send and test emails with Node).

How to send emails in Javascript (3 ways to send and test emails with NodeJS) About Sending emails is a core requirement of many modern businesses. Whether it’s invoice receipts, password resets, or support messages many applications send emails programmatically in response to different events. Sending emails these days is easy and doesn’t require knowledge of SMTP, POP3, or IMAP! Here are three ways to send email in NodeJS and how to test them.


Test REST APIs with Kotlin, Retrofit, and JUnit5

Test REST APIs with Kotlin, Retrofit, and JUnit5

Test REST APIs with Kotlin, Retrofit, and JUnit5 A common concern for any developer is whether their code works. Unit tests catch many simple errors but the only way to truly know whether an application is working as intended is with end-to-end (or E2E) tests. These are tests that emulate user actions to verify aspects of your app that are key to its success. Consider what is essential for your business: account creation, payment processing, event tracking.


Email API custom domain

Email API custom domain

Email API for custom domains If you have a custom email address that matches your companies domain you may wish to use it programmatically in code or tests. With MailSlurp you can keep access to your custom email address and also access it in scripts and code. Custom domain setup First register a free account with MailSlurp. Add your domain and follow the steps to verify your domain. Setup API access You can call the MailSlurp email API using the REST API or one of the many official SDK libraries.


Codeception wait for Selenium and Webdriver to start

Codeception wait for Selenium and Webdriver to start

How to wait for Selenium to start during Codeception tests If you test using PHP and Codeception you may have run into the issue of how to start Selenium before your tests. Some people use a wait or sleep command but here is a tip to automatically start Selenium during tests and wait for it to start: Configure acceptance.suite.yml With the RunProcess extension with can add a special timeout wait command to wait for Selenium to start before starting our tests:


Smoke-test your app with CircleCI and NodeJS (catching bugs quickly)

Smoke testing with CircleCI and NodeJS (how to catch bugs quick!) In this article I’ll explain what a Smoke Test is and why you should implement one to catch bugs early in your website, API, or application. What is a smoke test? A Smoke Test is a suite of end-to-end/integration tests that runs against your production application on a scheduled basis to detect potentially serious bugs or “fires”. If a signs of smoke is found, the Smoke Test should alert someone who can investigate.


How to test an email address

How to test an email address

How to test an email address There are many instances in which test email addresses are required: testing email campaigns; software development; and QA testing. MailSlurp is a free service for creating test email accounts that can send and receive emails from real addresses. Create a free MailSlurp account You can sign up for MailSlurp and then create an inbox. The inbox has an email address that can send and receive emails.


Do you really need MailChimp? (transactional emails with AWS SES, Terraform and Lambda)

Do you really need MailChimp? (transactional emails with AWS SES, Terraform and Lambda) What are transactional emails? Many applications need to send emails. Usually these emails are triggered in code in response to a given event, such as a product purchase. For this reason they are often called Transactional Emails. But an app or backend service can’t just send an email, it needs to have a SMTP server setup. Setting up email servers can be tricky, so a number of services exist for sending emails with API requests.


Email API for email marketing and more

Email API for email marketing and more

Email API for marketing and more. Build applications and social campaigns that customers trust with reliable email APIs for testind and development. Easy integrations MailSlurp has API SDKs in many languages: Example Create inbox Can list inboxes Send emails Receive emails Attachments Sent emails Extract content Create inboxes Send emails Receive emails Attachments Create inboxes List inboxes Send emails Send attachments Receive emails Extract content Download attachments Reply to emails Match and search Create email addresses Get an inbox Receive emails in code List inboxes Send emails Upload attachments Send attachments Wait for emails Receive attachments Wait for matching Extract content Create email addresses List inboxes Send an email Attachments Receive an email Receive attachments Create inboxes List inboxes Send emails Use attachments Receive emails Download attachments Create email addresses Send emails Receive emails Send attachments Create inbox Can list inboxes Send emails Receive emails Attachments Sent emails Extract content Create inboxes Send emails Receive emails Attachments Create inboxes List inboxes Send emails Send attachments Receive emails Extract content Download attachments Reply to emails Match and search Create email addresses Get an inbox Receive emails in code List inboxes Send emails Upload attachments Send attachments Wait for emails Receive attachments Wait for matching Extract content Create email addresses List inboxes Send an email Attachments Receive an email Receive attachments Create inboxes List inboxes Send emails Use attachments Receive emails Download attachments Create email addresses Send emails Receive emails Send attachments Language C# (.


Mailinator alternative

Mailinator alternative

Mailinator alternatives Mailinator is a popular email testing tool that let’s you create test email accounts. It is used by QA testers and developers to test email processes and application. Mailinator is quite old and lacks many modern features. An alternative is MailSlurp - a free email API with a powerful dashboard and libraries in many common programming languages. MailSlurp email service MailSlurp is an email test account service that lets you generate real email addresses in code or using a web app.


Introducing MailSlurp 2.0

Introducing MailSlurp 2.0

Introducing MailSlurp 2.0 I’m very happy to announce the release of MailSlurp 2.0. MailSlurp started as a free experiment and subsequently became quite popular. But the MVP experimental nature of its design meant it didn’t scale and was missing features. So with MailSlurp 2.0, the system was rewritten from the ground up, learning from user input to build a system that lasts. What is it? MailSlurp is an API for testing code with real email addresses.


Validate frontmatter markdown SEO metadata in Javascript

Validate frontmatter Markdown SEO metadata in NodeJS Many websites today are built using static site builders and markdown with embed data: the JAM Stack. Markdown alone is useful for writing content. Adding Frontmatter YAML headers to Markdown allows us to embed meta data for static site builders. To validate this content to SEO we will share a test. Hugo setup Say you have a website built with Hugo. You might want to read all the content and check that the title and description properties of the markdown are of an appropriate length.


The fastest way to start a typescript project (in 30 seconds)

Fastest way to start a typescript project Typescript sometimes has a reputation for being difficult to get started with. Modern tooling has really improved this situation and it is now very easy to create a new project and get up and running in no time. Create a new project (in 30 seconds) In a terminal on Mac OSX or Linux create a new directory and navigate to it using this command:


Stripe get all customers list

Stripe get all customers list (example) In this post we will share a quick tutorial on fetching all customers from Stripe using the Stripe API. The problem Stripe does not allow one to fetch all of one’s customers in one go. Stripe returns customers in paginated lists. This means we must paginate through the list in a loop using a startingAfter ID in batches of 100. Code example Here is an illustration of how to fetch all customers by paging through a list of customers from the Stripe API.


Show latest package version NPM

How to show latest package version in NPM NodeJS’s package manager NPM has a handy feature for listing outdated packages and updating selected packages to the latest version. The MailSlurp web app is built with NodeJS and Vue. We use the NPM outdated command to keep our packages up to date. Here is how. Showing outdated packages To see the old packages in a NodeJS project navigate to the project directory and run npm outdated.


Quick Start Javascript

How to send emails in Javascript (with examples) Introduction MailSlurp is a free API for sending and receiving emails from applications or tests. It is designed as a simpler, more powerful interface for SMTP mail servers. You can use MailSlurp for any email related process including testing and normal sending and receiving. Questions For any questions or issues please reach out any time via email. API Key All MailSlurp requests require an API Key.


nbsp

nbsp

  and space in HTML tips and techniques There more to white-space than the spacebar. Computers have many ways of encoding space in documents, be they emails, PDFs, or HTML. The non-breaking space character (&nbsp; character in HTML) is commonly used to separate strings and denote a string that should not be put onto a separate line after the space. What are HTML entities? In HTML or emails containing HTML some characters need to be encoded as HTML entities in order to be read by a computer.


Mailto links explained

Mailto Links Explained Mailto not working right? Chances are, you’re making a simple mistake that is causing your link to not open your default email client. Understanding a little about mailto link can also help. The link, placed inside of the <a> tag – like this <a href="email@example.com">mail me</a> – is used inside of HTML to open an email client with the email address inside of the tag. If you add commas, you can send the same email to multiple recipients.


Install Swift on Debian Buster

Install Swift on Debian (Buster) sudo apt-get update sudo apt-get install libncurses5 clang libcurl4 libpython2.7 libpython2.7-dev wget Download package wget https://swift.org/builds/swift-5.4.1-release/ubuntu1804/swift-5.4.1-RELEASE/swift-5.4.1-RELEASE-ubuntu18.04.tar.gz sudo mv swift*RELEASE* /opt/swift/ Export path Add Swift to your PATH variable using your shell’s config file. Zsh echo "export PATH=/opt/swift/usr/bin:$PATH" >> ~/.zshrc Bash echo "export PATH=/opt/swift/usr/bin:$PATH" >> ~/.bashrc Open a new terminal and type swift --version to confirm. Handle missing dependencies If you see: version `GLIBCXX_3.4.26' not found (required by swift) Try these steps:


How to start selenium in a background process and wait for it to start

Easily start Selenium Server in a background process - and how to wait for it to start If you write software or QA tests you may have encountered Selenium. It’s a popular browser automation tool used for end-to-end acceptance testing. This means you can test applications in a real browser like Firefox or Chrome using code. There are many frameworks that support Selenium (such as Codeception, Specflow, ThirtyFour, and JUnit) but many of them lack a clear way to start Selenium before tests begin.


GitHub CLI Auth with token from environment variable

GitHub CLI Auth with token from environment variable You can use the github cli to automate release processes in continuous deployment situations. In CircleCI for instance set a context environment variable to the GitHub token for your user. Then in a script echo the variable into a file and read that with the Github cli. Be sure to unset the environment variable to ensure that the CLI does not complain (It checks the environment before executing to find your token and prevent use).


Fetch error message javascript

Fetch error message javascript Response status codes are an important part of API design. They can inform a caller about why a request may have succeeded or failed. When using Javascript fetch to make HTTP requests an exception is thrown for any response with a code of 400 or more. This will cause a calling function to crash but luckily we can easily handle the situation with Javascripts try and catch keywords.


Email on Rails

Testing with real email addresses in Ruby (Rails, Rspec) Ruby on Rails makes building and testing applications a breeze. But when it comes to user sign-up and email verification how do we test it? We can mock the email steps in tests or test it manually with our personal addresses but wouldn’t it be better if we could test automatically with real email addresses? Imagine if we could smoke test this aspect of our app so that we know for sure that essential email related processes are behaving as we expect them to.


Email Generator

Email Generator

Email Generator You can create real email accounts online using email generators. These accounts can be used for software testing, social campaigns, or privacy. One free service for email generation is MailSlurp. Generate email accounts Sign up for MailSlurp and create real email addresses using the dashboard. Use custom domains You can create email address with custom domains that you own by following the custom domain guide.


Email attachment size limit

Email attachment size limit

Email attachment size limit Email API services like MailSlurp let you send and receive email attachments in code and tests. What is the maximum size of an attachment Is there an email attachment size limit? NO. Not officially. The MIME email specication makes no mention of a file size limit - it isn’t very clear about attachments in generally though. What defines an attachment? Attachments are just another part of an email message body.