A good e-mail message will communicate your thoughts quickly, clearly and concisely, says Sheryl Lindsell-Roberts, author of Business Writing for Dummies. Lindsell-Roberts shared her tips for effective e-mailing during a recent seminar.Treat subject lines like newspaper headlines. E-mail subject lines are your chance to quickly grab the reader\u2019s attention, so pack them with concise, detailed information. Poor: "Sales Report." Better: "Sales up 7 percent in third quarter." When you reply to an e-mail, use the subject line to convey the essence of your response.Write messages like you\u2019re telling the news. Get to the point quickly. Put the information that\u2019s most important to your reader in the first paragraph. Answer any questions\u2014who, what, when, where, why and how\u2014you think your reader will ask.Keep your e-mail messages short. Remember that many executives will read your e-mail on a handheld device, and those have small screens. Never write an e-mail message that stretches beyond two computer screens. Office tip: To communicate more detailed information, send colleagues to an intranet link.Remember your manners. Double-check the spelling of your e-mail recipient\u2019s address. Personal messages about health, job status or appointment changes are better conveyed in person or over the phone. Don\u2019t treat e-mail casually. Avoid sending any message you would be ashamed to see reprinted later.