You tell me frankly. I don't know, because we are not together. Recognition through letters does not make sense to me. I interpret as meaning only alphabetically.
You have told me openly. I do not know because we do not live together. Recognition through the letters do not make me get the feeling you know. I translated the meaning of the text.
You must tell me frankly. I don't know if we are not together. Perceived through the letter doesn't make me feel you. I translated according to literal meaning.