1. Try to not attach unnecessary files to your email, because they have nothing to do with your email and people don't really care about a cute dog.
2. It would be good to not overuse the high priority option, so people think that when something is high priority that it is actually worth the high priority option, also if you have something that you need to show them they might not look at it right away.
3. Try to answer their question as quick as you can because nobody wants to sit around reading your answer that could've been answered in three sentences.
4. Do your best to correctly use capitalization, usage, punctuation, and spelling because if you do an assignment for school and you don't use any of those, then your teacher will delete it without even looking at it.
5. Include a greeting in your email, so that people feel comfortable and welcome when they start reading your email.
6. Always use professional font so that someone can read it instead of trying to figure out what letter that is.