It means "love you" and is usually used between lovers, family members and close friends.
2. cheers?
It means "rejoicing", which is very casual. It is usually used between friends and close colleagues. When it seems more relaxed and casual, formal occasions are generally not used at the end of the email.
3. Take care
It means "take care of yourself" and is generally used between friends to show their concern for each other.
4. Thank you or thank you?
It means "thank you", Thanks are more casual, while "thank you" is more formal and usually used in work. If you ask someone to do something or help in your letter, you can end it with this.
5. Yours or your sincerity or sincerity
It means "loyal to you". This ending is more personal and polite. It can also be used in business emails and between people who know each other.
6. Sincere greetings
It means "by the way, I wish you good luck in your work". It used to be used at the end of letters to wish businessmen and the like, but it was usually written at the end of letters instead of congratulations.