Oh God, It's you!
That can or can't be good. Without any tone, I have to look for another sign, written sign, that express the true nature of word(s). Nevertheless, most of the time it's your personal relationship with your interlocutor be the judge of all written conversation. But, personal means personal. It does pretty well on certain occasion, still inadequate on another occasion.
"Oh God, It's you" may sounds like an expression of relief, an expression of happiness, yet it does sound like an expression of anger and hate, doesn't it?