How to write an email in English?
First: we start the email with :
From : Mark

Second
To : John

Third:
About: visiting the museum

Fourth: Introduction
I am happy to write to you this email.
How are you?.
It is my pleasure to write to you.

Fifth: the content
I want to tell you about my visit to the museum. I went with my friends. It was a very beautiful day. We watched a lot of monuments. There were many tourists from different countries. I want to visit this place again with you. I am waiting for you.

Sixth : the end
See you soon.
I am looking forward to seeing you.
With my best wishes.
Signature: Mark