Student or Learner
Is is necessary to mention "thanking you" in end of each and every letter. when it should normally be used? Please reply as soon as possible.
We might say "Thank you" in a letter but we would normally use it near the beginning - "Thank you for your letter of 12 September 2011..."
At the end of a letter, we might say "Thank you for your attention" or "Thank you for your consideration", but most formal letters end either "Yours sincerely" or "Yours faithfully".