Garrett Kuk at Focused Communication provides some very useful tips on making your email communication with a potential employer or contact as effective as possible:
Make it easy to say yes. If you’re asking for a favor or advice, limit their options. I recently requested advice on an upcoming presentation, provided my rough outline, and asked if I had omitted any big points. When asking a question, use a direct phrase and end with a question mark. “Can you put me in touch with your regional representative?” sticks out more than “I was wondering if I could get the name of your regional representative.” Don’t be passive.