Zendesk Regular Email Formatting

Notify-requester-of-comment-update.liquid

{% capture newline %}
{% endcapture %}{% capture htmlemail %}{{ ticket.latest_comment_formatted | split:"<table" | size }}{% endcapture %}{% if htmlemail == '1' %}{{ ticket.latest_comment.value }}
{% else %}{{ ticket.latest_comment.formatted_value }}{% endif %}
{% for attachment in ticket.latest_comment.attachments %}
Attachment: {{attachment.filename}} {{attachment.url}}
{% endfor %}
{% if htmlemail == '1' %}
{% for comment in ticket.public_comments %}{% if forloop.index > 1 %}{% capture preline_prefix %}
{% for i in (3..forloop.index) %}>{% endfor %}{% if forloop.index > 2%} {% endif %}{% endcapture %}{{ preline_prefix }}On {{ comment.created_at_with_time | date:'%a, %B %-d, %Y at %-I:%M %p' }}, {{ comment.author.name }} <{{ comment.author.email }}> wrote:{{ preline_prefix }}{% capture line_prefix %}
{% for i in (2..forloop.index) %}>{% endfor %} {% endcapture %}{{ line_prefix }}{{ comment.value | split:newline | join:line_prefix }}{{ line_prefix }}{% endif %}{% endfor %}
{% else %}
{% for comment in ticket.public_comments %}{% if forloop.index > 1 %}
<div>
On {{ comment.created_at_with_time | date:'%a, %B %-d, %Y at %-I:%M %p' }}, {{ comment.author.name }} <{{ comment.author.email }}> wrote:
<blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">{{ comment.formatted_value }}
{% endif %}{% endfor %}
{% for comment in ticket.comments %}{% if forloop.index > 1 %}</blockquote></div>{% endif %}{% endfor %}
{% endif %}

Notify-requester-of-created.liquid

{% capture newline %}
{% endcapture %}{% capture htmlemail %}{{ ticket.latest_comment_formatted | split:"<table" | size }}{% endcapture %}{% if htmlemail == '1' %}{{ ticket.latest_comment.value }}
{% else %}{{ ticket.latest_comment.formatted_value }}
{% endif %}
{% for attachment in ticket.latest_comment.attachments %}
Attachment: {{attachment.filename}} {{attachment.url}}
{% endfor %}

ZendeskEmailTemplate.html.liquid

<div dir="ltr">
<div style="color: #b5b5b5;">{{delimiter}}</div>
{{content}}
</div>

This Trigger template for Zendesk renders the ticket responses as a stock-standard email (except for the delimiter). Includes a properly formatted plaintext version, and blockquote nested HTML version.
Make sure you remove the formatting from the main email template too (mine is attached).

As you can tell, there are egregious levels of hax required to determine various things. Probably various little improvements to make in the template, feel free to suggestion improvements (or any issues).

To configure

1. Go to Settings > Email
2. Adjust the EmailTemplate to the slimmed down version.
3. Go to Triggers
4. Adjust the Notify requester of comment update trigger and assign the template attached.

Gmail screenshots

Text Version
http://monosnap.com/image/yIjaMzBsSDeDuoY3Z3C9fL2EVKg8Wy

HTML Version
http://monosnap.com/image/wILiKahLk37SA2kMu29s1mkDNoNgYE

Is this still valid? :)