Custom variables

The email_form module whas build because of the use of dynamic variables inside the template which is declared inside your template file and inside the {exp:reinos_email_form:form} tag.

Those variables are simply defined by declaring form fields. See the example page for a real use case.

In cases of an array defined like

<input name="test[]" type="checkbox" value="1"/>
<input name="test[]" type="checkbox" value="2"/>
<input name="test[]" type="checkbox" value="3"/>

This data is available inside your template as (notice the _pair at the end of your variable name)

{test_pair}
    {value}
{/test_pair}