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Ideally, your email address should be a variation of your real name, not a username or nickname. Use periods, hyphens, or underscores to secure an e-mail address that's just your name, without extra numbers or letters, if you can. For instance, coolguy007@theemail.com will seem unprofessional. Meredith.Athena.Calhoun@theemail.com, however, is suitable. Most email services now allow you the option to write using a variety of fonts and text styles. For a formal email, however, keep things conservative, with fonts like Times New Roman and Arial. Avoid decorative fonts like Comic Sans or Old English. In addition:  Write your email in a legible font size, such as 12 point type. Avoid special styles like italics, highlighting, or multicolored fonts unless they are warranted by the content and purpose of the email. Do not use all caps. These make it seem like you are shouting at the recipient. Use keywords in the subject line that suggest exactly what you are writing about, in just a few words. This helps make sure that readers don’t overlook your email because the subject line is missing, is too vague, or suggests the email is unimportant.  Subjects like “Quick question,” “Contacting you,” or “Email about an important matter” are too vague or obvious to be useful. “Schedule, Guest List, Lunch Requests, and Meeting Overview for March 12th,” on the other hand, is overwhelmingly long and covers several topics. “Meeting RE: damaged escalator on March 12th,” however is short and to the point. It alerts your recipient to a single primary topic and a specific date.

Summary:
Use a professional email address. Stick to a professional font. Use a short and accurate subject line.