Too many assume an informal of a tone in their business e-mails. Yes, with those you know very well, be as informal as you like. But for all other business e-mails, you should be as formal as possible until the situation clearly dictates otherwise.
Informality in business e-mail is like wearing a wrinkled suit, a tie with a stain or an outfit that is too tight or revealing. People notice you but for all the wrong reasons. You know folks who do this in your office or workplace — what is the perception they provide?
When you e-mail a new client, associate or partner, if you are informal (not addressing with respect, using proper grammar, sentence structure, spell check, etc.) your inquiry may not be taken as seriously. Nor will the perception of what you will be like to work with or do business with be positive one.
When e-mailing a group or new contacts that don’t know you very well, by being informal those that don’t know you may make incorrect assumptions as to your educational level or your expertise about the topic at hand. Professionals act and communicate like professionals at all times regardless of mode of communication or venue — that’s because they are professionals.
It will never cause any harm to use the epitome of formality when forging new business and professional relationships. Let the other side set the tone of their ongoing communications formality. That combined with your discretion will guide you as to when is best to begin a more informal approach.
Business is all about perceptions. That is why everyone spruces up their appearance off-line. Consider your business e-mails part of your online business wardrobe.