Well, you use thank you either if it's a formal letter (and in any part of it) or not while you normally use best regards at the end of a formal letter
To properly thank a professor in an email, begin by addressing them respectfully, expressing gratitude for their help or guidance. Be specific about what you are thankful for and how it has benefited you. End the email with a polite closing, such as "Sincerely" or "Best regards."
At the end of an email, it is common to write a closing such as "Sincerely," "Best regards," or "Thank you." This helps to convey professionalism and politeness in your communication.
To properly sign a letter, write your full name legibly in cursive or print below the closing phrase, such as "Sincerely" or "Best regards."
to end a perfect letter you could write sincerely, sincerely yours, very sincerely, or very sincerely yours
I usually use 'Best Regards', 'Regards', 'Thank You', or 'Best' and then my name, title, etc.
it means thank you.(: but it's also the closing of a letter.
You can use "Best regards," (followed by a comma) in the closing of a business or friendly letter. On the next line, you can write your signature. If you are typing the letter, leave a blank line between "Best regards," and your typed name. In the blank line, write your signature.
衷心的问候
よろしく Yoroshiku
Hi Boss thank you very much,lets hope for the best! Thanks and best Regards Sanjaya
The submitted words mean, "the two best years." Thank you for taking the time and trouble to properly write the word 'años' using an 'ñ.'
There can be as many as possible depending on how a person wants to write it , mostly generally used forms are Thanks & Regards, Sincerely, Best Regards, With Best Regards, Cheers, with Love etc