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

Latest posts and updates from the MailSlurp developers.

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What Is Amazon Simple Storage Service (SES) - And How Can I Use It?

Amazon SES is an email service among virtual servers, AI apps, and libraries. Ideally, you can integrate your email system with your program hosted on Amazon.

The Do's And Don'ts Of Mass Email Sending

Replace email blasts with safe transactional mail campaigns - preserve your spam core and deliverability.

Send emails in Swift 5 (on iOS, Mac, and Linux)

Send emails in Swift 5 (on iOS, Mac, and Linux)

SPF Records Explained: What Are They?

An SPF record is now required for reliable email delivery. It protects your emails from being faked. This protects you against phishing scams and trollers.

Maximum Email Size and How to Optimize It

Email sizes are fundamental for a few important reasons. One is security, and another is the performance of your email.

List of free Mailinator alternative

Free disposable email accounts for testing and development!

How to test an email address

Test email accounts for testing email addresses in code or online. Create fake email accounts for testing.

How to mask an email address

Email masking is more critical than ever before. Hide the data behind your address for privacy.

How to choose the right email design size (for various campaigns)

Email sizes can be instrumental to determine if your consumer will comprehend and engage with your content. While the template width (600 px) is typical, there are nuances to be mindful of. There are no hard and fast standards for email template height like design blocks.

HTML Mailto Links Explained

HTML Mailto is uncomplicated to use. This link opens the default email client and adds a new notification maker. Pre-populated fields save time and prevent email bounces. This post will cover customizing mailto. We'll also discuss its viability in this decade. Come on.

Create custom print classes with Tailwind

Configure tailwind.config.js to create prefixed classes with a custom media query.

Confirmation emails that work

Confirmation emails enjoy a 70% open rate; sending nominal "order confirmed" messages is inexcusable. We will teach you how to confirm an email in the article below.

Bounce email: verify address lists to reduce spam

Check email addresses exist before sending emails to reduce bounce-back returns and avoid spam bans.

&nbsp and HTML space tips and solutions

&nbsp, AKA non-breaking space, is a character used in HTML to create a white space. In this post we analyze usage and performance solutions.

Other

Who Invented Email?

American Ray Tomlinson and Shiva Ayyaduari are both created with conceiving of and creating electronic mail or email.

Which SMTP Port Should I Use?

Picking the right port for SMTP mailservers

Which Industries Require 2FA?

Two-factor authentication is common security requirement for many businesses. Adding MFA or 2FA user access to your organization or product is essential.

What's an SMTP port and How to Choose the Right One?

What's an SMTP port and How to Choose the Right One?

What is the difference between SMTP, POP, and IMAP?

Email is a technology built on several protocols that define message communication between servers and clients.

What is an email blast and how to avoid spam.

Email blast campaigns and how to maintain a good sender reputation.

What is an SMTP Server?

How do SMTP servers work and what is a fake smtp server

What is an SMS message segment?

Text messages are split into SMS segments when sent.

What is an Email Newsletter, and How to Create One?

What is an Email Newsletter, and How to Create One?

What is a transactional email?

Why sending emails via API services is simpler than deploying your own SMTP server

What is a Mail Transfer Agent?

Emails are sent and transfered between mail-servers using mail server transfer agents.

What is Single Sign-On, and How Does it Work?

What is Single Sign-On, and How Does it Work?

What is SMTP? Everything you need to know

Comprehensive SMTP guide for sending and receiving email with the simple mail transfer protocol.

What is SMS Authentication and is it Secure?

What is SMS Authentication and is it Secure?

What is SAML and How Does it Work?

What is SAML and How Does it Work?

What is Multi-Factor Authentication (MFA)?

What is Multi-Factor Authentication (MFA)?

What is Multi-Factor Authentication (MFA), and How Does it Work?

What is Multi-Factor Authentication (MFA), and How Does it Work?

What is MMS Messaging? And how is it Different from SMS?

What is MMS Messaging? And how is it Different from SMS?

What is DKIM Email

How to setup and configure DKIM signatures with the sender policy framework (SPF)

What are PTR Records and Why are They Important?

What are PTR Records and Why are They Important?

What SMTP Authentication Is, Why It's Important, and How to Use It

Email protocols like SMTP use authentication to verify secure sending and receiving of emails.

What Is a Mail Transfer Service (MTA)?

Email routing with MTA transfer is a common way send emails between servers.

What Is a Fake Smtp Server

How can fake mail servers be used to create real email accounts for testing and development. Use Smtp4Dev or MailSlurp for email generation.

What Is Webhook?

Use HTTP push webhooks to communicate between services in the cloud or your software. You can react to events when they occur in separate systems.

What Is Throttling?

Server throttling is the restriction of traffic over a network due to high demand or many requests in a row.

What Is SMTP?

SMTP is a email sending protocol that is used by mail servers to communicate messages.

What Is SMTP Rely?

An SMTP relay allows youy to send email through a relaying mail server. Use mail relay for sending bulk email campaigns that are time sensitive.

Validate frontmatter Markdown SEO metadata in NodeJS

How to parse and validate markdown with YAML headers and assert for required meta data lengths and properties.

Using test email accounts to test user sign up

Generate real email addresses in tests. End-to-end test user sign up with real email addresses.

Using List-Unsubscribe headers in emails

CAN-SPAM email regulations and the List-Unsubscribe SMTP header

Using Email APIs to send and receive emails

Generate dynamic email addresses on demand with MailSlurp - a modern email API.

User Authentication: Getting the Most Out of SMS OTP

User Authentication: Getting the Most Out of SMS OTP

Understanding the SMTP Queue and Managing Your Emails

use SMTP queue systems to enqueue email actions for later dates.

Transactional Email Services Compared

Sending emails is important for many applications. Top 10 transactional email services compared.

Top free tools for testing domain reputations

Test the spam ranking and domain authority of your site or mailserver with these free tools.

Top Testing Frameworks for Android UI

Top Testing Frameworks for Android UI

Top 3 email testing tools

Top 3 email testing tools

Tips for writing excellent email subject lines

Tips for writing excellent email subject lines

The ultimate guide to email testing tools

The ultimate guide to email testing tools

The ideal email design dimension for various campaigns

The ideal email design dimension for various campaigns

The complete guide to Email Marketing

The complete guide to Email Marketing

The best test email tools compared

How to test transactional email campaigns and email verification using the best free and paid tools.

The Working Principles of 2FA Hardware (two factor authentication)

UFA and 2FA provide secure authentication for single-sign on applications and is an essential part of modern development.

The Way to Ship a Text via Email (And an email through text): A Simple Guide

The Way to Ship a Text via Email (And an email through text): A Simple Guide

The Top 29 Email Automation Software Programs to Grow Your Business

The Top 29 Email Automation Software Programs to Grow Your Business

The Recommended Email size

The Recommended Email size

The Most Advanced Guide on Azure Email Sending.

The Most Advanced Guide on Azure Email Sending.

The Difference between POP3 Vs. IMAP Emails

The Difference between POP3 Vs. IMAP Emails

The Best Email Deliverability Testing Tools

The Best Email Deliverability Testing Tools

The Best Email Deliverability Testing Tools

Test your email delivery using MailSlurp to ensure high email marketing success.

Text Enabled Toll-Free Numbers: What all Businesses Should Know about Toll-Free SMS

Text Enabled Toll-Free Numbers: What all Businesses Should Know about Toll-Free SMS

Testing with real email addresses in Ruby (Rails, Rspec)

Testing user sign-up with real email addresses in Ruby

Testing email delivery (top sites compared)

Comparison of popular email testing tools versus MailSlurp

Testing TOTP one time passwords

How to test multifactor authentication end-to-end using email traps to capture OTP tokens.

Testing Content Security Policy CSP Headers

Testing Content Security Policy CSP Headers

Test user sign up with NodeJS and Jest

How to use test email accounts with Jest and NodeJS. Send and receive email from code to test user sign up end to end. Generate unique email addresses and then receive real emails to verify email confirmation codes.

Test email accounts

Use MailSlurp to create email addresses to send and receive emails during tests.

Test SMTP servers with Telnet

How to use Telnet to test the SMTP servers?

Test REST APIs with Kotlin, Retrofit, and JUnit5

Fast, strongly typed end-to-end testing

Ten best email fonts that always work well

Ten best email fonts that always work well

Stripe get all customers list (example)

Stripe get all customers list (example)

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

Avoid embarrassing bug reports by catching bugs in production early with Smoke Tests. It's a simple way to deploy with confidence.

Show latest package version NPM

Show latest package version NPM

Should I Use Mailinator for Email Testing?

Mailinator is a free disposable email testing tool.

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

Sending emails in NodeJS with Sengrid, SES, or custom SMTP servers.

Send attachments with an Email API

How to send email attachments using MailSlurp API.

STARTTLS vs SSL vs TLS

Secure email transmission uses transport layer security with secure sockets layer to encrypt sending and receiving.

SMTP Relay: How to Test a mailserver Relay

Inspect mail relay with tools like TelNet, SMTPCli and MailSlurp

SMTP Port Guide

SMTP Port Guide

SMTP Email Delivery Services

Check email deliverability using DKIM SMTP

SMTP Commands and Response Codes List

A full list of commands and response status codes for SMTP mail servers when sending emails.

SMS txt shortcodes explaines

SMS txt shortcodes explaines

SMS Intercept Attacks and Why SMS Multi-Factor Still Matters

SMS Intercept Attacks and Why SMS Multi-Factor Still Matters

SAML SSO identity providers compared - top 10 single sign-on IdPs

Top 10 SSO identity providers compared

Reformat .NET core projects using Resharper CLI tools

Reformat .NET core projects using Resharper CLI tools

Receiving emails in tests

Generate email accounts for testing

Receive email in code and tests

Use MailSlurp email APIs to fetch and process emails in tests or apps.

React server side rendering in express (typescript guide)

Use JSX and TSX in your express.js project to render static HTML strings.

Quick Start Javascript

Starting sending and receiving emails in no time with MailSlurp's official NodeJS Client.

PHPMailer tutorial (Sending email with PHP)

PHPMailer tutorial (Sending email with PHP)

OTP SMS verification tutorial

OTP SMS verification tutorial

Noreply Email Address

Noreply Email Address

NodeMailer NPM Tutorial

Send and receive email using NodeMailer in Node JS.

Multiple SPF records for one email domain

Pros and cons of creating more than one SPF send policy framework record

Multi-factor Authentication Guide

Multi-factor Authentication Guide

Multi-factor Authentication (MFA): All You Need to Know

Multi-factor Authentication (MFA): All You Need to Know

Markdown Heading Sizes

How to specify headers h1, h2, h3 and more in Github flavoured Markdown

Manage Email Throttling Correctly!

Manage Email Throttling Correctly!

Mailto links tutorial

Tutorial mailto links in HTML emails

MailJet send email tutorial

Using MailJet to send emails (and how to test it).

MailHog

MailHog

Learn the Right Way to Calculate Email Open Rate

Learn the Right Way to Calculate Email Open Rate

Keeping your email marketing list clean - avoiding bounces and complaints

Keeping your email marketing list clean - avoiding bounces and complaints

Introduction To Mailcatcher

How to create email workflows with MailCatcher and what alternatives exist?

Instant messaging platforms compared

Use SMS/TXT messaging platforms to send and receive text at scale

Install Swift on Debian (Buster)

Install Swift on Debian (Buster)

Hugo responsive image srcsets

Serve responsive picture tags with custom render-image layout partial in Hugo static site generator.

How to wait for Selenium to start during Codeception tests

Example tutorial for how to wait until webdriver and Selenium have started during Codeception PHP tests

How to use Mailto links

Mailto links not working guide.

How to use Laravel's notification system (PHP tutorial)

Check new notifications queued in PHP using Laravel's email and SMS notification system.

How to test that an email is received using Cypress JS.

Use Cypress JS to test emails are received and validated during end-to-end testing.

How to test OTP (one time passwords)

Many applications use OTP one time passwords to secure their data. See how to test OTP using real email addresses.

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

Spawn Selenium server process before tests start for easier acceptance testing.

How to set the same property twice with React inline styles

Lately when needing to provide Webp background image image-sets I discovered a way to set the same React inline style property twice.

How to send emails in Javascript (NodeJS)

JS SMTP email sending guide using HTML and NodeJS.

How to send email in R

RLang tutorial for sending emails over SMTP.

How to send confirmation emails

How to send confirmation emails

How to send and receive email with Amazon SES

Use SES in Amazon Cloud to manage transactional emails.

How to send an email using Powershell (Windows and cross-platform)

Use Send-MailMessage in Windows Powershell to send emails using an SMTP server or MailSlurp's free email API.

How to override appsettings.json values with environment variables in .NET

You can set configuration options in Dot NET Core using prefixed environment variables.

How to install Conda on Linux/OSX for python

Conda is a package management system that is popular in the machine learning and python space.

How to fix the any package by glob error in dotnet

Fix .NET installation on Linux for missing dotnet dependencies.

How to filter exclude logs for containers in EKS FluentBit CloudWatch plugin

How to filter exclude logs for containers in EKS FluentBit CloudWatch plugin

How to add google fonts to Tailwind CSS custom config (NextJS example)

Tailwind CSS is a powerful frontend framework. Customize your tailwind theme using GoogleFonts and CSS variable syntax.

How to Send an Email in Python

Send emails using SMTP mailer in Python. Detailed tutorial for sending mail in Python.

How to Send Mass Email with Gmail

Mass ending sending is possible with Gmail bulk access.

How to Schedule a Text Message

How to Schedule a Text Message

How to Create Compelling Email Subject Lines to Increase Open Rates

How to Create Compelling Email Subject Lines to Increase Open Rates

How to Check Your Domain Reputation?

How to Check Your Domain Reputation?

How To Prevent Email Spammer Bot?

Configure your mail server to avoid spam bots from infiltrating your emails.

HTML entities NBSP in emails

HTML entities NBSP in emails

GraphQL Email API Tutorial

Did you know you can send and receive emails using GraphQL?

GraphQL API disposable email accounts

How to create real email addresses using GraphQL to send and receive emails in tests and frontend applications.

Grab all details about an SMTP Port

What are common SMTP mail server ports and how do you find them?

GitHub CLI Auth with token from environment variable

How to set GitHub CLI token in terminal without a file

Generate test email accounts

Test applications with real emails. MailSlurp is like a fake email account or test account for testing email functionality.

Generate random disposable or permanent email addresses

Generate random emails in code or visual dashboard.

Fetch error message javascript

Handle response exceptions with Fetch in Javascript

Fastest way to start a typescript project

Modern typescript tooling has come a long way. See how to setup a new project with TS-Node, TSC, and typeconfig.json.

Fake email generator tutorial

Fake email accounts for QA testers and developers

Extensive Information on LDAP

Extensive Information on LDAP

Explaining Cloud Email with Options to Think About

Explaining Cloud Email with Options to Think About

Everything You Need to Know About SMTP Security

Everything You Need to Know About SMTP Security

Email verification and deliverability testing with MailSlurp

Email verification and deliverability testing with MailSlurp

Email marketing campaign bulk email testing

Send bulk transactional emails with MailSlurp online or in code using CSharp, Node.js, Java, PHP and more.

Email for testing

Test email accounts for email testing. Alternatives to Mailinator, MailTrap, Mailosaur and more.

Email attachment size limit

Email MIME type message attachment file size limits and conventions

Email address case sensitivity explained

What are the rules for email address matching. Are they case sensitive or insensitive?

Email Testing Checklist

10 quick tips for testing an email before you send it.

Email Over Blockchain

Can emails be sent over blockchain? Well kind of! LedgerMail and other and at the cutting edge of decentralized email.

Email Obfuscation: What it is and How to Use it

Email Obfuscation: What it is and How to Use it

Email Generator

Fake email account generator for testing and development. Create real email accounts for automation, privacy, and software development.

Email CSS: How to Improve Your Emails With CSS?

Email CSS: How to Improve Your Emails With CSS?

Email Bounces: What to Do About Them?

Email Bounces: What to Do About Them?

Email API for email marketing and more

APIs for email marketing and social campaign testing. Send, receive, validate and test emails in code and online.

Email API custom domain

Hosted email domains for custom mail servers

Effective Welcome Emails

Effective Welcome Emails

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

Create cross platform build scripts for DotNET Core in a way similar to Makefiles.

Do's and Don'ts for multiple SPF records

What SPF records are and how to manage them. SPF is a form of TXT record that verifies a domain is authorized to send and receive email.

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

Sending transactional emails with AWS is more powerful than other API providers but comes with some downsides.

Disposable email accounts for DotNET core 6

Create real throw-away email addresses for testing and development in .NET core. Follow this guide to get started.

Determining When to Send Emails to Increase Open Rates, Click Rates, and Sales?

Determining When to Send Emails to Increase Open Rates, Click Rates, and Sales?

Detailed Instructions for Fixing the 550 XXX Error

Detailed Instructions for Fixing the 550 XXX Error

Deploy Redash to AWS with Terraform

Easily deploy a self-hosted Redash instance to an AWS EC2 machine using Terraform.

Create and publish OpenAPI Java clients using Gradle and Maven S3

Create and publish OpenAPI Java clients using Gradle and Maven S3

Create a new .NET MVC project starter (with the CLI)

DotNet starter project MVC generation using the command line interface.

Cold Emailing in Compliance with CAN-SPAM

Email can spam regulations for better sender reputation.

Cold Emailing in Compliance with CAN-SPAM

How to maintain a strong sender reputation and delivery when cold emailing

Cloud email services compared

An introduction to cloud email APIs

Can you add Gifs to emails? (Kind of!)

Add gifs to emails for more engagment

CC and BCC in SMTP

CC and BCC in SMTP

Best SMS apps for android

Best SMS apps for android

Best 4 frameworks for evaluating web-based applications

Best 4 frameworks for evaluating web-based applications

BIMI email records - a replacement for DKIM?

What is a BIMI Record and how can BIMI prevent email spam and spoofing?

Avoiding Spam Filters

Avoiding Spam Filters

Autogenerate SDK clients for .NET APIs using Autorest and OpenAPI

How to create API libraries for your DotNET project using SwashBuckle Swagger annotations and build-time client generation

Authentication vs. Authorization: What You Need to Know About These Security Processes

Authentication vs. Authorization: What You Need to Know About These Security Processes

Are Email Addresses Case Sensitive?

Are Email Addresses Case Sensitive?

All you need to know about smtp4dev

All you need to know about smtp4dev

All You Should Know About Playwright

Browser automation is a way to control Chrome, Firefox, Safari, and Edge using code or recorded actions.

All You Need To Know About Content Marketing

All You Need To Know About Content Marketing

Affiliate Marketing: What it is and How to Start Using it

Affiliate Marketing: What it is and How to Start Using it

A fake SMTP server setup for testing.

A fake SMTP server setup for testing.

1111 SMTP Connections failing

1111 SMTP Connections failing

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Email testing guide
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