Qfyilyi

Recently I'm thinking which one got correct grammar?

Mail written for Bob

or

Mail written to Bob

Notice mail is noun.

Both two sentence sounds correct, but why most people say mail written for Bob not mail written to Bob? Do mail written to Bob has correct grammar or it's wrong?

I am not the greatest at deciphering the English language (although it is my first and only language), but it seems to me that "for" implies that Bob had someone else do some writing "for" him to be sent to someone else. Whereas, the "Mail written TO Bob" is something he received from someone else.

When mail is written for Bob, it can mean either that it is addressed to him/to be given to him, or that it was written for his benefit (=on behalf of). The latter is clear if you had something like Bob had broken his arm, but he needed to get a letter to his friend, so Joe wrote the letter for Bob. In this example, for absolutely means that it was written on his behalf. However, in a sentence like the letter was written for Bob, without context, most readers would assume it meant the letter was addressed to him.

If mail is written to Bob, it can only mean that it is addressed to him. Because of this, using 'to' avoids any confusion. Using 'for' is still completely correct, but if you use it, you might need to clarify what you mean.