__________ (Company name),
Date: __/__/____ (Date)
Subject: Thank you for the promotion
My name is __________ (name) and I have been working in _______ (department) of your reputed company as __________ (mention designation). My employee ID is _________ (mention your employee ID here).
I am highly thankful to you for providing me with an offer of promotion. I believe I could be a perfect fit for the designation provided to me. I am highly delighted to see that you are looking at me as capable of the same.
___________ (Mobile number)