Short answer:
Use a mailto: link with parameters to prefill subject and body text, and apply inline styles to control the appearance.
Mailto snippet with subject, body text, and styled link:
<a href="mailto:((Email))?subject=A Subject&body=A Body" target="_blank" style="color:#000001;text-decoration: none;">
<span style="color:#000001">
((Email))
</span>
</a>This creates a clickable email link that opens a new message with a predefined subject and body.
How to choose Outlook to open when a mailto link is clicked:
How Outlook opens when an email link is clicked:
