It looks like OutSystems inlines the font-style in addition to having the font style in the <style> section in e-mails, and it seems to get confused.

Looking at some sample output emails with View Source when it gets to the destination:

<style>
...
.ContentsText {
 font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;
}
...
</style>

<div class="ContentsText" style="font-family: arial, " helveticaneue?,helvetica,sans-serif;?="">

I'm not sure why it has to inline it as well as having the style section, but I could see some e-mail client somewhere requiring it. That said, it should probably take quoted fonts into account for the inlined version!

-- Ritchie

Interestingly, OutSystems seems to figure it out a little better if the text is in a link:

<a id="wt15" href="mailto:me@me.net"><span class="ContentsText" style="font-family: arial, & quot ;helvetica neue & quot ;, helvetica, sans-serif;">me@me.net</span></a>

I had to separate out the & quot ; like that or the forum just turns it into a quote :)