Sendune: Open Source Marketing & Customer Engagement

What is Sendune?

What it is

Sendune is an open-source HTML email template editor and no-code designer written in TypeScript and packaged as an Angular library. It was originally built for use within Sendune, formerly Send With SES, and it offers a public live demo at designer.sendune.com. The project sits in the Angular and AWS SES email template ecosystem, where teams need to create and export email HTML without a full marketing platform.

The concrete problem it solves is the gap between hosted email builders and direct HTML editing. Sendune produces direct HTML output, avoids intermediate markup such as MJML, and lets users save templates for use with any email service provider. It supports transactional and marketing email design with a minimal interface rather than a heavy feature set.

Key capabilities

The drag-and-drop designer lets users build transactional or marketing templates without writing code, and the README says users can create and save unlimited templates across three template types.
The HTML code editor supports reuse of existing HTML templates or coding templates from scratch.
The plain text mode supports simple transactional messages, matching the README guidance that transactional emails are often best delivered as plain text.
The output is direct HTML rather than an intermediate format such as MJML, so templates can be exported and used with any email service provider.
Image handling is pluggable: the library accepts application-provided upload and selection triggers, and users can store images in AWS S3, Cloudflare R2, or GCP Cloud Storage.
The interface can be themed through CSS imports and variables, allowing an embedding application to adjust icon, header, text, and border colors.

Who uses it and how

Product teams can install the library in an Angular application and embed the email designer inside their own marketing or customer engagement workflow.
Marketers and operations users can start with the drag-and-drop designer, switch to the HTML editor for existing templates, or use plain text for simple transactional messages.
Sendune users can design templates in the hosted demo, send a test email, and save the HTML output for AWS SES or another email service provider.
Self-hosted teams can connect the editor to their own image storage and upload logic, keeping email images under their chosen cloud storage controls.

Getting started

Users can try the hosted demo at designer.sendune.com, open the StackBlitz Angular 15 example, or install the package with npm or yarn. The README names the npm package as @send-with-ses/ng-email-designer.

When to use it — and when not to

Use Sendune when you want a lightweight, open-source Angular email designer that outputs direct HTML and can be embedded in your own product. Avoid it when you need fine-grain controls such as line heights, a mature contributor base, or a turnkey service that also manages image storage. The README emphasizes minimalism, and the repository metadata shows zero listed contributors, so operational maturity may be limited.

project readme (upstream, from github) — read inline

💌 Free, Open Source, HTML Email Editor and Designer.

sendwithses-opensource-drag-and-drop-html-editor

👹 Who?

This email designer was originally built for use within SENDUNE (formerly Send With SES).

⁉️ Why Choose SENDUNE Email Designer?

Truly Open Source: Use it for personal use or commercial use or whatever.
Truly Free: Because the ones that say 'free', are not.
Truly Works: Because the ones that are free don't seem to work.
Truly HTML: No intermediate code wranglers like mjml.
Truly Fast and Light Weight: Because you have better things to do with your time.
Truly No-Code: Design like a pro without coding headaches. Our minimal interface gets out of your way.
Truly Democratic: Save HTML output as a template and use with ANY email service provider.

3️⃣ Three Ways To Create Templates

Comes with three template types that let you design any kind of transactional or marketing emails. Altogther, you can create and save unlimited templates.

Drag and Drop Designer - Start designing beautiful emails immediately.
HTML Code Editor - Reuse HTML templates that you already have or code them from scratch.
Plain Text Emails - 'Minimalists'. This is for you.

🚀 Built On Solid Fundamentals.

Follows a few fundamental rules to design emails that work in nearly all email clients (web and mobile). It is built upon some great work done by these people.

Ted Goas - https://www.cerberusemail.com
Nicole Merlin - https://www.emailwizardry.com.au
Mark Robbins - https://www.goodemailcode.com

🎪 Live Demo.

Play around with the live demo at https://designer.sendune.com. You can design a template and send yourself a test email.

👩‍💻 Installation

(This StackBlitz demo is built with Angular 15. The same process should work with other Angular versions.)

Install via NPM:

npm install @send-with-ses/ng-email-designer

Or via YARN:

yarn add @send-with-ses/ng-email-designer

🖼️ Image Handling

You can use a cloud storage of your choice (ex: AWS S3, Cloudflare R2, GCP Cloud Storage etc) for storing your images. Please implement your image upload functionality and provide it to the library as below (imageUploadTriggered/imageSelectionTriggered).

<lib-email-designer #emailEditor class="px-0"
        [type]="selectedTemplateType" [template]="selectedTemplate"
        (imageSelectionTriggered)="onImageSelectionTrigger($event)"
        (imageUploadTriggered)="onImageUploadTrigger($event)"
        (emailContentChanged)="onEmailContentChange($event)"
        >
</lib-email-designer>

Click here for more documentation

🎨 UI Theming and Styles

You can make a few changes to make the Email Designer match your website colors.

Import the following styles into your global styles file (e.g., styles.scss):

@import '../node_modules/@send-with-ses/ng-email-designer/src/lib/theme.scss';
@import '../node_modules/@send-with-ses/ng-email-designer/src/lib/email-editor.css';

To make the Email Designer match your website's UI, include the following in your main.scss or styles.scss file and change the colors as you like.

 :root {
    --sws-icon-color: #ccc;
    --sws-icon-hover-color: #555;
    --sws-header-background: #eee;
    --sws-header-text-color: #555;
    --sws-border-color: #ccc;
 }

🤝 Contribute.

Feel free to fork the repository, make improvements, and submit pull requests.

🐛 Issues or Ideas:

Spotted a bug or got an idea? Just open an issue or write to designer at sendwithses dot org.

⭐ Minimal Rationalism (Optional Reading)

SENDUNE Designer focuses on simplicity and ease of use over a heavy feature set. Over years of sending emails, we've come across some email patterns that work and many that don't. Some are design related while some are organisation related. Let's break some bubbles here - in no particular order.

Remember, you are designing an email, not a website. If you want fine-grain controls like 'line heights', you are at the wrong place.
The more you nitpick on the design, the more likely it will break in email clients. (i.e. more moving parts == more breakages).
Transactional emails are best delivered in plain text.
For best results, HTML emails (transactional and marketing) must (mostly) fit 'above the fold'.
Rethink your design if it is more than one scroll depth.
The combined time spent by all the recipients who opened your marketing email will be lesser than the time you spent designing it. (This statement is an exaggeration, but you get the drift.)
Emails are being designed to impress bosses, not the end readers.
Avoiding spam folders is largely a function of the content of your email. Technology or the pedigree of your email sending service cannot help you if your content is unsolicited.
The top three email service providers control ~80% of the market. They can break you.

Frequently asked questions

Is Sendune free to use?

Sendune is open source under the MIT licence. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does Sendune do?

Simplify AWS SES email management with ease

What is Sendune written in?

Sendune is primarily written in TypeScript. Its source is publicly available at https://github.com/sendwithses/drag-and-drop-email-designer, and it has 2,308 GitHub stars.