You probably send out many emails on a daily basis. As part of work, to friends and family or to chase up something. When writing your email, try to remember your tone, It's easy to believe you can get away with being rude via email. As you type, imagine you are speaking to the person face to face and keep your tone polite. Think about how it feels when you receive a rude email. Also, if you ask for help via email and they give it, it never hurts to acknowledge that help with a quick thanks.