Should the 1st(first) letter in each word be capitalised?
I used to ask people to correct anything I write, not just the actual words in question, in my signature box. And it helped. So please don't mind now that I'm returning the favour.
I just realised that you wrote "to whom this may concern". "To whom it may concern" is the right phrase to use if you want to address someone whom you don't know yet in a letter. It's quite formal.