Emailing a professor to confirm grades is generally acceptable, especially if it includes a polite inquiry about potential errors and expresses gratitude for the semester. Professors recognize that students may want to ensure their grades are accurate, and many are willing to help clarify any discrepancies. However, concerns about privacy may prevent professors from discussing grades via email, leading them to prefer in-person discussions. It's important for students to approach this matter with evidence of any potential errors rather than vague complaints, as professors typically base grades strictly on established criteria rather than personal impressions. While some professors may find frequent grade inquiries frustrating, most will not hold it against a student if approached respectfully and with factual support.