letter for foreigner company

Dear friends
Hi
I want to know which points must be obey in a letter for a foreigner company? could you please help me
I wait to your reply
Bye

Dear Hamid,
It depends on what you want to write,
But the rules is just the rules of a formal letter , which you can find in any book, but if there's any special thing you want to mention , tell us about it.

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It should be Foreign Company

Foreigner (is a person)l