Email Composer, the Drag-and-Drop Template Builder

Our drag-and-drop email editor makes it easy to create beautiful messages that can be used for a wide variety of email sends: a newsletter, product announcement, promotion, or triggered email, like welcome series or order confirmations.

In Sailthru, Templates are used as the blueprints for all emails, and Email Composer is the easiest way to build them and to craft the content that will be sent to your recipients. Its drag-and-drop interface enables you to produce a well-designed message with a number of built-in features:

  • No knowledge of HTML is required, yet the addition of custom HTML is supported
  • Emails adapt automatically to smartphones and other small-screen devices
  • Open-tracking is automatically turned on; no need to embed a Sailthru beacon
  • Add special links with the click of a button, including links to user-specific unsubscribe pages and to web views of email content.

Email Composer is currently great for fulfilling ad-hoc email needs, but for emails that will include dynamic article or product recommendations, or require custom Zephyr logic or CSS styles, we recommended that you instead use Sailthru’s HTML Template Editor.

If this is your first time building templates for Sailthru, or you’re building a new type of template for the first time, be sure to discuss your plans with your Customer Success Manager. Your CSM can ensure you are using Sailthru’s best practices for template design and email strategy.

Some email clients impose a size limit on the HTML content of your messaging. Conventional wisdom says this is 102KB, excluding images. This limit may be subject to change, depending on the email client.

Every HTML element must be defined on the backend, which can increase the size of your HTML.To deal with this limit in Email Composer:

  • Minimize the number of elements like empty rows you use.
  • Use padding instead of a divider to keep your message weight low.
  • Start with clean plain text and apply formatting from there. If you’re changing text formatting, strip the existing formatting before applying anything new.

If you have any questions, reach out to Support or your CSM for help.

How it Works: An Overview

Within the Sailthru interface, email templates created with Email Composer are labeled as visual templates while others are labeled HTML templates, but both can be selected and used by our system in the Campaign workflow, Lifecycle Optimizer, and API.

Here’s a high-level look at the process of building a new email with Email Composer.

  1. In My Sailthru, on the Templates page, create a new visual email template.
  2. In Email Composer, drag in the desired structure blocks (to represent the email layout), then drag content blocks into them as needed. Common content blocks are text areas or images.
  3. For each content block, you can edit the content–write text, select an image, etc. You can also choose to hide content on mobile.
  4. Preview the template in both desktop and mobile formats, then send a test email to yourself or your team.
  5. For a one-time send, create a Campaign and select your newly created template. To set up the template to send as-needed, based on user status or behavior you can use one of the following methods:
    • Select the template in a Lifecycle Optimizer flow.
    • Have a developer use the Sailthru API (from your server) or JavaScript functions (from the user’s browser) to send the template in response to certain actions.

Build a New Template

  1. In My Sailthru, from the Messaging menu, select Templates.
  2. Click New Template.
  3. Enter a Template Name in the New Template box and select the Template Type “visual email”.
    • Optional: If your account has Teams enabled, you can restrict this template to certain teams.
      • To add a team, click the gray bar and select a team. Repeat to add more teams.
      • The template is visible and usable by all employees in your Sailthru account if you don’t select teams.
  4. Click Create Template. The new template opens in Email Composer.
  5. Set a Subject Line and Preview Text:
    1. Click “Not Set” under Subject Line and Preview Text to open the editor.
    2. Enter your preferred Subject Line and Preview Text.
    3. Click Apply to add them to your template.
  6. Set a From name, From email address, and optional Reply-To email address:
    1. Click “Not Set” under From to open the editor.
    2. Enter your preferred From name and From email address. You can also enter a Reply-To email address in this editor.
    3. Click Apply to add them to your template.
  7. Click the gear icon next to the From options. This opens the Template Settings editor.
    • In the first tab, select your Content & Data settings.
    • In the second tab, select your Links & Tracking settings.
  8. Finish designing your email with Email Composer.

You can find your email by the Template Name you set in the first step. It will be referred to by the Template Name throughout the Sailthru platform.

The Settings Editor

Configure settings for your templates in the Settings editor. Open the Settings Editor by selecting the gear icon next to the Save button.


Customize global template settings from the General tab.

Link Tracking

Note: Link tracking must be turned on for Sailthru to track link clicks.
Turn on Link Tracking to track link clicks from your emails and attribute those clicks back to unique users.

Google Analytics

Turn this option on to identify traffic coming from your emails in Google Analytics.

This automatically appends five utm parameters to your email links for tracking purposes:

  • utm_campaign: will automatically be the name of the campaign as it appears in Sailthru.
  • utm_medium: will automatically be “email”.
  • utm_source: will automatically be “Sailthru”.
  • utm_term: will automatically be the name of the sending list as it appears in Sailthru.
  • utm_content: if you are sending an AB Split or AB Winner or Auto Winner Campaign, this utm parameter will be added to your links. For segment A, the value will be “A”, for B, “B” and “Final” for the Final version of the AB Winner/Auto Winner test.

You can use Google Analytics independent of Sailthru Link Tracking.

Transactional Email

Mark your template as a Transactional message

Link Domain

Select a link domain from the drop-down menu. Set the domain in your My Account section if you want Sailthru to rewrite the links in your email to point at your subdomain, for example,

Load Promotion Codes

Select a promotion from the drop-down menu to associate single-use codes with your template. 


Set team permissions from this tab. Select your team or teams from the dropdown menu to give them access to your template.

Ad Plan

Set the ad plan you wish to use with your template. 

Auto Append Link Parameters

To change the utm_medium parameter or to add new utm parameters for Google Analytics tracking, use the Auto Append Link Parameters field. Write the new or current parameter with its value. For example, utm_medium=MorningEmail

Note: You must save your template to confirm the changes. If you do not save your template, the team permissions will not be applied.

Content & Personalization

Easily select a Data Feed and apply a Personalization Type in the Content & Personalization tab:

Data Feed

Select an existing data feed to dynamically populate variables from your site at send time. When you select a data feed, the items will populate in the window to the right. When you select a Personalization Type, the items will reorder.

Personalization Type
Select None, Interest, or Random to personalize content for users.


Add advanced Zephyr configurations to filter or sort the data feeds used in the template. Setup runs once for each customer send. This allows the Zephyr used to help personalize template variables, anything from the personalize function to setting a date to be included in URLs. Learn more in the Zephyr documentation and examples library.

For information on conditional Zephyr in your template, see Zephyr Display Rules and Conditions.

Drag and Drop Builder

Email creation and editing is divided into two main areas. The Canvas, where you will drag and drop content and structural elements to view the progression of your email’s design, and the Configuration panel where the drag-and-drop options and their properties live.

Image 2018-09-24 at 5.20.47 PM

The Configuration panel has three tabs to help control the appearance of your email: Content, Rows, and Settings.


On the Settings tab, you can set global properties for your email.

  • Content area width – Set the width, in pixels, for your email’s body. This is a fixed width and only applies to desktop. When viewed on a mobile device, your structure is converted to a single column that matches the width of the user’s device.
  • Background color – Set a default color to apply to the background of your email. Choose transparent to not set a color.
  • Content area background color – Set a color to apply to the content width area of your email. When used in conjunction with the background color it can create a distinct area to highlight your message.
  • Default Font – Global font used for all text, except any text blocks where you have specified a different font.
  • Link Color – Set all links, including newly created links, to a specified color.


Next, you’ll set up the layout of your email using rows. Rows serve as containers for the content in your email, including text and images. The following are available on the Rows tab:

Single Column section-1-single
Centered Double Column section-2-centered-double
Left-Offset Double Column section-3-left-offset-double
Right-Offset Double Column section-4-right-offset-double
Triple Column section-5-triple
Quadruple Column section-6-quadruple

Every new template starts with a single-column structure in place, ready to receive a content block. (This is covered in the next section, Content. For example, you might drag in an image to create a hero image.)

The rows can also be stacked on top of each other. For example, a three column structure could be placed beneath the hero image’s single column, to display three featured products or articles.

The use of the editor’s column structures helps ensure mobile responsiveness without any extra configuration or code. By default, adjacent columns will stack on top of each other when the email is viewed on a small screen. Columns that run left to right will display top to bottom. There is, however, an option to disable stacking for any email.


Custom Columns

Create custom-sized columns for your templates. Three of the pre-built column structures allow for customizing the columns. From the Rows tab, under Empty Rows, look for the column structures that contain dashed boxes. They’re outlined in orange in the following image:

Column structures with customizable column structures highlighted

Drag your selected row onto your template. Select the row to open the Row Properties in the Rows tab. From the Customize Columns section, you can set the column size and add new columns to customize your layout.

Use the two rows of dots between each column to resize the column width. Select a column to show the column settings options. If you need to delete a column, select the column and click delete.

Display Rules and Conditions

Apply display conditions at the row level.

  1. Select a row in your template to open Row Properties in the Row tab.
  2. Click the Add/Edit Display Rule button.
  3. Add your initial rule in the Add/Edit Display Rule modal. Click Add to save your rule.
  4. Your rule is added to the row.
  5. To edit the condition, click the Edit condition button. When the Edit modal opens, you can edit any of the content, including the {if} statement.
  6. Click Confirm to finalize your rule and apply it to the selected row.
Zephyr Display Rules and Conditions

If you need to add more complex display conditions, use Zephyr. You can either add conditional logic at the template level and run a check on a row or add conditional logic at the row level.

Add a Template-Level Variant and a key/value Check

Selecting Add/Edit Display from the Row editor prompts a conditional row, allowing for a key/value pair check.
Note: The value assumes a string. Entering a numeric or boolean value is not advised.

To use non-string fields and/or more customized logic, create template-level variables in Setup using Zephyr conditionals. Find the Setup section under the Advanced tab in Email Settings. Select the gear icon next to the Save button to open Email Settings.

Zephyr conditionals can be as simple or complex as you’d like, allowing you to check for the existence of a boolean, if a numeric value is between a certain range, and more:

{*Check if a boolean value is true*}
{if my_boolean_var}
   {show_prompt_1 = "yes"}
{*Check if a numeric field equals 1*}
{if my_numeric_var == 1}
   {show_prompt_2 = "yes"}
{*Check if numeric field does not equal 2*}
{if my_numeric_var != 2}
   {show_prompt_3 = "yes"}
{*Check if numeric field is between 10 and 20 OR a boolean field is not false*}
{if (my_numeric_var >= 10 && my_numeric_var =< 20) || my_boolean_var != false}
   {show_prompt_4 = "yes"}
{*Check if a variable false/null/doesn't exist*}
{if !my_other_var}
   {show_prompt_5 = "yes"}

Then check if your new field is equal to the value you set. Select the Add/Edit Display Rule button to add your check:

The Custom Field contains your key and the Field Value contains your value.

Add Logic in the Editor

  1. To add conditional logic directly in the editor instead of creating custom fields in Setup, select your row and then the Add Condition button to open the editor.
  2. Add a name and description for your condition.
  3. Add the opening conditional logic in the Before field. This usually starts with {if...}
  4. Add the closing to the After field. The editor should resemble the following image:
  5. Select Confirm to add your condition.

Saved Rows

Saved rows help you streamline your template creation process. Create a universal header or footer once and use it across all your email messaging. Either process - saving or using a saved row - requires only a few steps to complete.


  • It is not currently possible to delete or rename Saved Rows.
  • Your Saved Rows appear in the order you created them, starting with the most recent.
  • If you can't find your row, use quotation marks around the name when searching. This returns an exact value.
Create a Saved Row
  1. Select the row you would like to save.
  2. Select the save icon from either the row itself or the row properties menu.
  3. Give your row a name and select Create Saved Row. Your saved row will be available.
Use a Saved Row

When you're using a Saved Row, you can edit the row within a template. The edits you make will only affect the template, not the Saved Row itself.

  1. Select the dropdown menu under Rows.
  2. Select Saved Rows from the menu.
  3. Search for or scroll to the saved row you would like to use.
  4. Drag the saved row to your template as you would with any other row.


Now that the layout of your email is in place, add the visual components by dragging them from the Content tab into a row. Multiple Content blocks can be added into one row.

Content blocks already in place can be reordered or moved to a different structure by selecting them, then clicking and holding the access arrows email-composer-arrows  while dragging to the desired location.

Once you add your first content block, you'll see an Undo option History, Undo, and Redo buttons that appear in the lower left corner of your designer. appear in the lower left corner of your canvas. The buttons include Undo, Redo, and a History icon. Selecting the History icon shows a timeline of your last 15 edits within the current browsing session.

The content blocks create the primary visible elements of your email body. Each of the content types is described below: Text, Image, Button, Divider, Social Icons, Video Link, and HTML Block.

Every block's padding, or separation, can be set in its Properties panel under Block Options. You can also choose to hide content when an email is opened on a smaller mobile screen.

Find the Block Options section in the Content Properties.


To add text to an email, select the content tab and drag the Text content block into a structure. You will see the following text appear.

"I'm a new Text block ready for your content."

Click anywhere on that sentence to edit the text (you can triple-click the text to highlight and replace it). A number of text formatting tools is displayed:

  • font family
  • font size
  • bold, italics, underline, and strikethrough
  • text alignment
  • numbered and non-numbered bullets
  • text and background color
  • link text
  • special links are also available here for:
    • User-specific unsubscribe
    • View online
    • Forward to a friend
    • Anonymized link for sharing

Collapse the floating editor using the Collapse button .

Note that if you set the font family to Global Font, it will inherit the font family selected under the SETTINGS tab. This allows you to change the font family for multiple elements at once just by changing that property in the Settings tab.

Request Custom Fonts

If you want to use web fonts from sites like Google Fonts, ask Sailthru to include the font as an option for your Email Composer messages. To be accessible in customers' emails, the font must be a web-accessible font. If you use Typekit fonts, see the Custom Font Resources section.

Note: Some email clients, such as Gmail, will not render web fonts. We highly encourage you to provide us with a recommended "font-family stack", which should include a web-safe font or general font family style (such as sans-serif.) For more information on font-family stacks, see the Custom Font Resources section.

How to Have a Font Added
  1. Locate the font's link on Google Fonts or a similar site. You can request an unlimited number of fonts.
  2. Send the name of your account(s), the font link or links, and your recommended font family stack to Sailthru Support.
  3. A team member will confirm the font addition or respond with further questions. Once successfully submitted, please allow up to one week for the a font to be added to your account.

If you have any questions, contact Sailthru Support.

Custom Font Resources

The Image block comes with an image uploader to receive your images. You can either drag an image file on top of this block or click "Browse" to reuse images from your account or other services. You will have several methods for uploading images, including a file upload, upload from a URL, import from services like Instagram, as well as a free image search.

By default, images will automatically be sized to fit the structure within which they are contained. This is the recommended setting to ensure images resize correctly for any screen. However, you can disable automatic sizing and set the image to be a percentage of the structure's column.

Use the Properties panel to set the alternative text as well as any destination URL. If you intend on populating the image with a dynamic image like a countdown timer or an advertisement, you can select "dynamic image". This will allow you to set a dynamic image for the send while still viewing a sample image in the composer.


  • When uploading an image with the same name as an existing image in Visual Composer, the image will take approximately 1 hour to propagate to any templates using the image. Make sure to wait for the image to propagate before sending. This restriction only applies to replacing images. New images will immediately propagate.
  • The maximum allowed file size is 20MB.
  • Animated GIFs wider than 1920px will be resized on upload and become static images. We recommend using GIFs under 1920px in width.
  • All image file types are allowed.
  • Total image storage is not currently capped for the lifetime of your Saithru account.

Insert a call-to-action button that can open a web page in the user's browser. Alternatively, buttons can be set to send an email, make a call, or send an SMS from the user's device to your chosen recipient.

Selecting the text of the button in the canvas will provide a limited text editor. The action and destination URL are set in the Properties panel, where you can also set the button's background color and text color, border, width, and roundness.


A customizable horizontal rule. For an invisible spacer, set to Transparent.


A configurable set of social network buttons. Choose a design in the Properties area, then configure which networks to include and your ID/address for each.

You can also include custom social buttons by clicking Add new icon.


Using your own code may affect how the message is rendered. Make sure to use correct and responsive HTML. Where possible, is recommended to build with the editor's options instead, to ensure code is valid and the design is responsive.

To add an HTML block to your template in Email Composer:

  1. Decide on your template formatting. If you're using the available row structures, drag them into place on your template.
  2. Drag an HTML block from the Content Pane to your desired location in your template.
  3. Click the HTML block. The Content Properties pane opens for your HTML block.
  4. Add your HTML content.
  5. Finish editing your template.


  • Using includes is supported in HTML blocks, but is not a best practice. Using includes can require additional custom code to ensure it smoothly relates to a visual template.
    Format your include to resemble the following: {include 'include name'}. Remember to check your content width settings.
  • Make note of the following when using Zephyr in Text blocks and/or HTML blocks:
    1. The syntax Zephyr uses for conditional logic is not fully supported in Text blocks. To ensure your content will render correctly, move any Zephyr that uses any of these characters: &,>,<,&amp,&gt,&lt into the setup tab. Once there, reference the Zephyr logic from inside the Text blocks using variables.
    2. When using HTML blocks with Zephyr, we recommend disabling HTML Sanitizer. Please contact support to proceed.
  • Depending on your use case, you may use Display Conditions on rows that contain HTML and/or Text blocks in place of Zephyr.

Add a YouTube or Vimeo URL to automatically generate a preview image. The image will link to the provided URL in a new tab.

Previewing Email

You can quickly check what your email will look like on desktop or mobile sized screens. In the dropdown on the save icon, select "preview". This will take you to a new view where you can toggle between a larger desktop view and a 320px mobile screen. 

To test the email in real email-client apps or share it with other stakeholders, you can send a test email. In the dropdown on the save icon, select "test send". These sends have the word [TEST] prepended to the subject line and will not contribute to any reporting. However, in most other respects, they will resemble production sends. When you click "test send", you can specify the recipient address.

Email Client Test

Test your email templates across 70+ email clients and browsers with the Email Client Test tool.

  • See a high level view across different categories:
    • Web
    • Mobile
    • Application
  • Click in to see specific preview details

Follow the steps below to generate previews for a template:

  1. Open the template you want to test in Email Composer.
  2. Open the dropdown menu on the Save button and select Preview.
  3. Click the Email Client Test button in the right side of the Preview window top menu.

    The Email Client Test opens in a new window or tab.
  4. Check that the subject line, preview text, and email address are correct and then click the Run Test button.
  5. View the results of your test to make sure that your template is ready to send. The results screen breaks the results into categories for Web, Mobile, and Desktop Applications.