{% macro get_subject() -%}
Survey "{survey_title}" for event "{event_title}" has started.
{%- endmacro %}
{% macro get_html_body() -%}
Dear user,
The survey "{survey_title}" in the event "{event_title}" is now open.
You may answer the survey by clicking the link below:
{survey_link}
Best regards
{{ session.user.full_name }}
{%- endmacro %}