Business Insider asked etiquette experts when it's appropriate to send a handwritten thank-you note. They said a note is essential after staying at someone's home or receiving a personalized gift.

Remember the last time you got a real letter in the mail? Not a bill, coupon, or invitation. And, not even a thank-you note.

In a world where communication is often reduced to quick texts and social media posts, the art of expressing gratitude can sometimes be overlooked. Many people wonder whether they really need to write ...