Glad that you've brought this question.
I think it is very foraml and good expression to know about.
Okay! Here it is!
In English, when you write emails or letters to someone, you would put or say something nice right before your name such as... "cheers", "best", "sincerely", and so on.
Korean people do the same! We would write something nice when we end emails or letters, and now you've just witnessed one of them - 드림.
드림 (deu-rim) or 올림 (ol-rim) used when writing emails or letters to elders such as grand-parents, parents, employer, superiors, teachers...
드림 & 올림 literally means "giving" 드림 and "presenting" 올림.
But the meaning is acutally more than that! Of course, it contains its literal meaning but, it also implies the meaning of "respect" and "sincerity"
Therefore, 드림 means "giving" with respect and sincerity
올림 means "presenting" with respect and sincerity.
Whenever I write letters to my grand father and my parents, I also use them.
But thesedays, many kids and young generation have lost a sense of "respect", "love", "sincerity"... How sad it is! What's worse is, many young parents today don't guide and teach their kids/children about the manner of writing emails/letters. (I think...)
I hope my explanation helps you understand.
cheers,
Tim 드림 ("Giving" with respect and sincerity)^^
