language is a funny thing. it's simply symbols that represent ideas. communnication is what you should be shooting for though, and printed text just lacks most of what communication involves. you can't see a cheeky smile in Times New Roman no matter how hard you try
body language is 90% of communication. so yes, i say keep it strictly business in e-mails. the basic 5, who, you and her, what, have a plan, when, have a time, where, refer back to what, and ias always for why, because you're the prize she's after after. good luck