I don't pretend to know everything about recruiting email templates or outreach to niche candidates. But I know this. Cliches and corporate-speak won't do it - for them or anyone else. I can recite half of these recruiting email templates from memory. 

"I came across your resume, and I'm highly interested in your skills and background. Would you be interested in a 15-minute conversation to discuss this role in more detail? I can tell you why my client is so special, and this is the job for you."

I have some questions. 

1. Did you come across my resume in a bar? In a forest? My background isn't a meadow - it's my career You didn't come across anything, so get to it. 
2. Highly interested in my background, huh? Why didn't you mention one detail that would prove you even looked at it? 
3. These calls never take 15 minutes. 
4. I know "special client" is code for something bad. 

I have an entire series of faces I make when I read this junk. 

I have a lot of thoughts on how you get it right. Hell, I have a book on writing better emails. But here's the TL;DR version and my favorite email template.