Hi Matias,
isn't working
Should always be accompanied by a description of the failure.
Even though... that image has some issues, and I see you got it from the help.infiniteautomation.com page about custom email handlers. I will put something better there, since that image is riddled with problems.
For now, try,
<@subject>Hey - Stuff is happening with the automation system and I think you should know</@subject>
<#if renderedHtmlPointValues??>
<#list renderedHtmlPointValues as renderedPvt>
${additionalContext.temperature.deviceName} - ${additionalContext.temperature.name} - ${renderedPvt.value} - ${renderedPvt.time}<br/>
</#list>
</#if>
And be sure to add a point into the context with the key 'temperature'
Also it should be noted the renderedHtmlPointValues and renderedPointValues items are only added to the model if it's a point event and the point that generated the event is running.
You could add recent values into the model yourself in the script by doing something like,
model.put("temperatureValues", temperature.last(10));
And then using the <#list> to iterate over that, instead.