Sub: [What the letter is about]
Dear [Ms./Mr. Last name],
Thank you so much for interviewing me [Date]. I appreciate it.
I am excited about the prospect of joining a company that I have long admired.
I am writing to let you know how much I appreciate the time you spent getting to know me. I find your enthusiasm for growing the company's talent extremely contagious and look forward to experiencing your leadership on a daily basis.
I am also excited about the company's People Partners project. Your 'INtrepreneur' observation hit the nail on the head.
Incidentally, I made a similar suggestion as a trainee at [Company] in [Year] and was consequently made the HR manager of the equity analysis division.
I would also like you to know that my meeting with some of your HR managers and employees could not have gone any better.
Thank you for suggesting I meet with them.
Not only did they come across as true-blue professionals, interacting with them helped vindicate my decision to pursue what might be the most critical phase of my HR career at [Company] and none other.
I look forward to meeting with you soon and welcome any questions and suggestions you may have.
Thank you, once again.