Remember what I said about grammar errors being a telltale sign of a small company? I sincerely cannot even believe this happened, but Express — the national clothing chain, one I’ve frequented since I was 12 — sent me this e-mail this morning. The critique has nothing to do with their new points/rewards program. The fact that a huge national brand has a copywriter who was either unskilled enough to not know the difference between your and you’re or was too “n00bish” to not proofread is just about unforgivable. A small…