Edit Order confirmation adding on if Vendor option

[JessTNB]

Hey,

I'd like to send a message in the Order Confirmation email to those who ordered at least one item from a certain vendor (Warehouse). I created the following script, but it doesn't work:

{%- if line_item.vendor == "Warehouse" -%}
<p> <font color="red">PLEASE NOTE:</font> <font color="blue">Your order contains a Special Order item(s) – This will ship within 2-4 weeks of placing your order. We will provide additional tracking information to you upon dispatch.
{% endcase %}
Regarding the tracking status of your order, the first piece of communication you will receive is the fulfilment notice; confirming your item has been picked at our partner warehouse and is on its way to us at TNB Records Australia (you will typically receive this notification within 24 hours of your purchase).The next piece of communication you will receive will be when your item ships from our warehouse here in Australia. This will include your Australia Post tracking number which you can then use to track the item to your doorstep. </font></p>

<p><font color="black">If you have any questions or concerns, please don’t hesitate to contact us. </font></p>
{% endif %}

Can you help me on how to correct it? 

Thank you!!