zulip/templates/zerver/emails/missed_message.subject

{% if show_message_content %}
    {% if group_pm %} Group PMs with {{ huddle_display_name }}
    {% elif mention %} {{ sender_str }} mentioned you
    {% elif private_message %} {{ sender_str }} sent you a message
    {% endif %}
{% else %}
    New missed message{{ message_count|pluralize }}
{% endif %}
{% if realm_name_in_notifications %} in {{ realm_str }}
{% endif %}