Emails with dynamic content

There are two supported approaches for sending emails with dynamic content:

Template language (recommended)
- Use the templateLanguageVersion=2 parameter in your API request.
- Allows more powerful syntax for substitutions, logic, and expressions.
Legacy handlebars helpers
- Do not set templateLanguageVersion in the API request.
- Still supported for backward compatibility.

See the Send fully featured email (opens in a new tab) API endpoint for the full API reference.

Refer to the Template language and Legacy handlebars sections below to learn more about these two approaches.

Template language (recommended)

To send emails with dynamic content, use the template language within your HTML content and define placeholder values in the to or default parameter of your request.

You can add any available template language constructs to handle substitutions, conditional statements, or iterations directly in your email template.

For details, see Template language.

Legacy handlebars helpers

Legacy helpers use the familiar {{#helper}} ... {{/helper}} syntax. These are still supported, but we recommend migrating to the new template language for future-proof projects.

Legacy handlebar helper examples

HTML request	To JSON request	Resolved HTML
Helper example: #eq
{{#eq name "Bob"}}    Dear {{name}}   {{else}}   Hi {{name}}   {{/eq}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob"    }  }	Dear Bob
Helper example: #each
{{#each friends}} Hi {{this}} {{/each}}	{    "to": "[email protected]",    "placeholders": { "friends":["Bob","John","Jack"] }  }	Hi Bob Hi John Hi Jack
Helper example: #unlessEq
{{#unlessEq name "Bob"}} Dear {{name}} {{else}} Hi {{name}} {{/unlessEq}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob"    }  }	Hi Bob
Helper example: #default
Hi {{name}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob"    }  }	Hi Bob
Helper example: #gt
{{#gt age 12}} Welcome {{name}}! {{else}} Hey {{name}}, you are under age {{/gt}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Hey Bob, you are under age
Helper example: #lt
{{#lt age 12}} Welcome {{name}}! {{else}} Sorry {{name}}, This is kids arena {{/lt}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Welcome Bob!
Helper example: #equalsIgnoreCase
{{#equalsIgnoreCase gender "male"}} Dear Mr {{name}} {{else}} Dear customer {{/equalsIgnoreCase}}	{    "to": "[email protected]",    "placeholders":{    "name": "Bob" , "gender": "MALE"   }  }	Dear Mr Bob
Helper example: #gte
{{#gte age 12}} Welcome {{name}}! {{else}} Hey {{name}}, you are under age {{/gte}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Hey Bob, you are under age
Helper example: #lte
{{#lte age 12}} Welcome {{name}}! {{else}} Sorry {{name}}, This is kids arena {{/lte}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Welcome Bob!
Helper example: #compare
{{#compare name "!=" "Bob"}}Hi {{name}}{{else}} Dear Bob{{/compare}}	{    "to": "[email protected]",    "placeholders": {    "name": "Jane" , "age":10   }  }	Hi Jane
Helper example: #equals
{{#equals name "Bob"}}    Dear {{name}}   {{else}}   Hi {{name}}   {{/equals}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob"    }  }	Dear Bob
Helper example: #lessThan
{{#lessThan age 12}} Welcome {{name}}! {{else}} Sorry {{name}}, This is kids arena {{/lessThan}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Welcome Bob!
Helper example: #lessThanOrEquals
{{#lessThanOrEquals age 12}} Welcome {{name}}! {{else}} Sorry {{name}}, This is kids arena {{/lte}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Welcome Bob!
Helper example: #greaterThan
{{#greaterThan age 12}} Welcome {{name}}! {{else}} Hey {{name}}, you are under age {{/greaterThan }}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Hey Bob, you are under age
Helper example: #greaterThanOrEquals
{{#greaterThanOrEquals age 12}} Welcome {{name}}! {{else}} Hey {{name}}, you are under age{{/greaterThanOrEquals }}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Hey Bob, you are under age
Helper example: #when
{{#when name "!=" "Bob"}} Hi {{name}}{{else}}Dear Bob{{/when}}	{    "to": "[email protected]",    "placeholders": {    "name": "Jane" , "age":10   }  }	Hey Jane
Helper example: #contains
{{#contains friends "Bob"}} Hi {{this}} {{/each}}	{    "to": "[email protected]",    "placeholders": { "friends":["Bob","John","Jack"] }  }	Hi Bob
Helper example: #and
{{#and great magnificent}}Bob{{else}}Jane{{/and}}	{    "to": "[email protected]",    "placeholders": { "great": true, "magnificent": true }  }	Hi Bob
Helper example: #formatNumber
{{#formatNumber price}} {{/formatNumber}}	{    "to": "[email protected]",    "placeholders": { "price":10000 }  }	10,000
Helper example: #isTruthy
{{#isTruthy Male}}Hi Bob{{else}}Hi Jane{{/isTruthy}}	{    "to": "[email protected]",    "placeholders": { "Male": true }  }	Hi Bob
Helper example: #isFalsey
{{#isFalsey Male}}Hi Bob{{else}}Hi Jane{{/isFalsey}}	{    "to": "[email protected]",    "placeholders": { "Male": true }  }	Hi Jane
Helper example: #ifEven
{{#ifEven age}}Hi Bob{{else}}Hi Jane{{/ifEven}}	{    "to": "[email protected]",    "placeholders": { "age": 20 }  }	Hi Bob
Helper example: #ifOdd
{{#ifOdd age}}Hi Bob{{else}}Hi Jane{{/ifOdd}}	{    "to": "[email protected]",    "placeholders": { "age": 20 }  }	Hi Jane
Helper example: #ifNth
{{#ifNth age balance}}Hi Bob{{else}}Hi Jane{{/ifNth}}	{    "to": "[email protected]",    "placeholders": { "age": 20, "balance": 20000 }  }	Hi Bob
Helper example: #is
{{#is name "Bob"}}Dear {{name}}{{else}}Hi {{name}}{{/is}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Dear Bob
Helper example: #isnt
{{#isnt name "Bob"}}Dear {{name}}{{else}}Hi {{name}}{{/isnt}}	{    "to": "[email protected]",    "placeholders": {    "name": "Bob" , "age":10   }  }	Hi Bob
Helper example: #neither
{{#neither great magnificent}}A{{else}}B{{/neither}}	{    "to": "[email protected]",    "placeholders": { great: true, magnificent: false }  }	B
Helper example: #not
{{#not great}}A {{else}} B{{/not}}	{    "to": "[email protected]",    "placeholders": { great: true, magnificent: false }  }	B
Helper example: #or
{{#or great magnificent}}A{{else}}B{{/or}}	{    "to": "[email protected]",    "placeholders": { great: true, magnificent: false }  }	A
Helper example: #unlessGt
{{#unlessGt physics chemistry}}Hi {{name}}your score in Physics :{{physics}}{{else}}Hi {{name}}your score in Chemistry : {{chemistry}}{{/unlessGt}}	{ "to": "[email protected]",    "placeholders": {    "name": "Bob" , "physics": 70 , "chemistry": 75 }  }	Hi Bob your score in Physics : 70
Helper example: #unlessLt
{{#unlessLt physics chemistry}}Hi {{name}}your score in Physics : {{physics}}{{else}}Hi {{name}}your score in Chemistry : {{chemistry}}{{/unlessLt}}	{ "to": "[email protected]",    "placeholders": {    "name": "Bob" , "physics": 70 , "chemistry": 75 }  }	Hi Bob your score in Chemistry : 75
Helper example: #unlessGteq
{{#unlessGteq physics chemistry}}Hi {{name}}your score in Physics : {{physics}}{{else}}Hi {{name}}your score in Chemistry : {{chemistry}}{{/unlessGteq}}	{ "to": "[email protected]",    "placeholders": {    "name": "Bob" , "physics": 70 , "chemistry": 75 }  }	Hi Bob your score in Physics : 70
Helper example: #unlessLteq
{{#unlessLteq physics chemistry}}Hi {{name}}your score in Physics : {{physics}}{{else}}Hi {{name}}your score in Chemistry : {{chemistry}}{{/unlessLteq}}	{ "to": "[email protected]",    "placeholders": {    "name": "Bob" , "physics": 70 , "chemistry": 75 }  }	Hi Bob your score in Chemistry : 75

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