Dovetailer: HTML Email Generator
- HTML and text versions
- Nunjucks support
- Sass support
- Markdown support
- Reset styles
- Responsive support
- HTML minification
- Development build for more efficient development and debugging
- Automatic special character replacement
- In HTML version, converts special characters to HTML entities
- In text version, replace non-ASCII characters with ASCII equivalents (ex: smart "curly" quotes are replaced by dumb quotes)
- CSS Transformations
- HTML Transformations
npm install dovetailer --save-dev
Dovetailer comes with two methods out of the box:
compileDirectorycompiles all of the emails in your templates directory, and saves them to the file system
compileEmailcompiles only a single email template and returns the result without saving to the file system
templatesPath(STRING, required): filepath to your email templates
doctype(STRING): a custom doctype if the HTML4 doctype isn't sufficient
whitelistSelectors(ARRAY): selectors to not automatically strip from the HTML. For more info, see here.
const compileDirectory =return
example-gulpfile.js and an
example-config.js in this repository that you can use as a base for your development environment. It requires Gulp and BrowserSync. I think this a great way to use Dovetailer in development, but you can use Dovetailer however you like. Coming soon: a starter project that you can fork to get going quickly.
To compile a single email template, you can use the
templatePath(STRING, required): filepath to email template
extraContext(OBJECT, optional): data to override context
const compileEmail =
Writing Your Own Emails
templatesfolder, add another folder for the new template you want to build. Name this folder whatever you want to call your email template.
In that folder, add the following files:
html.njk: your Nunjucks template for the HTML version
style.scss: your main Sass file (these styles will be automatically inlined)
text.njk: your Nunjucks template for the text version
context.json: the data file used by Nunjucks to compile your template
reset.scss: your Sass file for custom reset styles (see Reset Styles below)
You can also add additional files and folders in your template directory such as Sass partials. See the
example template for, well, an example.
Development and Production Builds
The development and production versions of your email should always render exactly the same (see below) in the browser. There is no development build of the text version, only the HTML version.
The main difference between the development build and the production build is the development build references external stylesheets. The external stylesheets have sourcemaps that point back to the original Sass files. This makes it much easier to develop and debug your emails.
You should use the development build when you're working on coding an email and you're viewing it in a web browser. You should never try to actually send a development build, even just as a test to yourself. It definitely won't work at all.
Great, but...the development and production builds aren't rendering the same for me!
The production build moves the media queries into the head and groups the styles together by media query. Since CSS is order dependent, in some cases this can produce unexpected results. However, if you follow best practices and keep your Sass organized, you can avoid these issues.
Including "reset" styles helps ensure that your emails render the same across all email clients. There are two different types of reset styles: reset styles that need to be included in the
<head> of the email and reset styles that need to be inlined. Generally,
<head> reset styles are client-specific hacks.
Accordingly, in the included
common folder, there are two reset files named
reset-inline.scss. These are the default sets of reset styles that are included automatically in every email. These files are the result of our research and have been thoroughly tested.
This requires no configuration, but if you want to specify your own set of reset styles for an individual email, you can do so by adding files named
reset-inline.scss to your email's template folder.
If you want to build a responsive email, you're going to need to use media queries. Since it's impossible to inline media queries, your responsive styles will be injected into the
<head> of your HTML.
No extra configuration required! Your media queries will automatically be extracted from your CSS and injected. Also, if you have multiple of the same media query in your stylesheet, the selectors will all be grouped together into a single media query.
For styles in media queries to take any effect in HTML emails, they need to override the internal styles. So, the compiler automatically adds the
!important directive to all styles in media queries.
All compiled Sass files are also run through Autoprefixer, which in most cases will actually act as a minifier by removing extraneous vendor-prefixed styles.
Media query declarations in the same media query rule are packed into one media query rule using CSS MQPacker. This enables you to nest media queries inside of any style rule in Sass without having redundant media query rules in your compiled CSS.
<table>) always get the following HTML attributes:
Empty table cells (
<td>) are automatically filled with a non-breaking space (
). An "empty" table cell is defined to be any table cell that contains either no characters or whitespace only.
Anchor tags (
<a>) always get the following HTML attributes:
<img>) always get the following HTML attributes:
height styles are always applied to
<img>s as width/height HTML attributes.
Dovetailer does its best to look up the dimensions of any
<img> image. It will automatically inject those dimensions as
height HTML attributes as well as
height inline CSS styles. If the image name ends in
@2x, it will assume the image is retina quality, and divide the dimensions in half. Similarly,
@3x images will have dimensions divided by 3. If you specify width/height values for an
<img> using CSS, the natural dimensions are overridden. Image dimensions are cached; if you want to invalidate the cache you can delete/modify
- If you rename a directory in the
templatesfolder while Gulp is running, it will crash Gulp.
- Adding a directory in the
templatesfolder while Gulp is running causes an infinite loop?
- Improve error handling of email compiles that result in
- Improve caching mechanism for image dimensions
- Easy mechanism for dates in copyright statements
font-familystyle from empty table cells
- Replace attributes like
- Outlook margin support
- Add command line flags:
- Beautifying production HTML
- Disabling development version
- Automatically ensure that empty table cells have
- Resolve adding/renaming templates issues
- table attributes ordered: width, height, cellpadding, cellspacing, border
- Automatically convert responsive styles to use the
- Move common build folder elsewhere
- BrowserSync - CSS injection on dev build
- Automatic Gmail Promotions tab code generation
- em/rem to px converter
- relative img references
- W3C validation