Looking on the internet deeply has found these results:

I write this letter to tell is the most popular phrase on the web.

I am writing this letter to tell 1109,000 results on the web	I write this letter to tell 1119,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Dear Russ, I am writing this letter to you... because we once meant a great deal to each other... and there's no one else to whom I can go for help. "I am writing this letter in front of your house." Dearest India, I'm writing this letter to you from Florence. "I am writing this story for him..." This is the reason why I am writing a letter to you because I feel really bad inside my stomach. But I have so much free time, so I am writing this second letter. I am writing on behalf of my parents... who appreciated your letter to them about my brother's death. I'm writing this letter to you, because of your tolerance.	I'm hesitating even as I write this letter "The absence of our Umberto means that I write this letter in haste..." Did you write this letter to Mr. Alfredo Hartman? To tell you the truth, I don't quite know how to begin this letter to you. Dear Butch, when your mother was sick, She didn't want me to write no letter and tell you, Even when they took her to the county hospital. 'Dear Grace. 'I write this letter to you with a heavy heart. As I write this letter, the ocean breeze feels cool on my skin. As I write this letter, I know it will never be read.

I am writing this letter to tell

1109,000 results on the web

I write this letter to tell

1119,000 results on the web

More popular!

Dear Russ, I am writing this letter to you... because we once meant a great deal to each other... and there's no one else to whom I can go for help.
"I am writing this letter in front of your house."
Dearest India, I'm writing this letter to you from Florence.
"I am writing this story for him..."
This is the reason why I am writing a letter to you because I feel really bad inside my stomach.
But I have so much free time, so I am writing this second letter.
I am writing on behalf of my parents... who appreciated your letter to them about my brother's death.
I'm writing this letter to you, because of your tolerance.

I'm hesitating even as I write this letter
"The absence of our Umberto means that I write this letter in haste..."
Did you write this letter to Mr. Alfredo Hartman?
To tell you the truth, I don't quite know how to begin this letter to you.
Dear Butch, when your mother was sick, She didn't want me to write no letter and tell you, Even when they took her to the county hospital.
'Dear Grace. 'I write this letter to you with a heavy heart.
As I write this letter, the ocean breeze feels cool on my skin.
As I write this letter, I know it will never be read.