Go into the email knowing your goals. Avoid rambling on and on or writing a lengthy letter about yourself. If you're emailing to ask for clarification or an answer, ask for specific guidance and not general observations, suggests Wharton business professor Adam Grant in the Psychology Today article "If You Do This, Your Emails Might Be Rude." For example, instead of writing a novel-length email to your new mentor about your graphic design woes, try a focused question along the lines of, "I'm creating a gold-and-purple logo for a sports team, but it doesn't pop -- how do you think I could improve it?"
Write out all of your words in full. Don't use slang or cute abbreviations. While writing IDK to your BFF is acceptable, when you're emailing someone who you just met, stay on the more formal side. The other person may not use acronyms or slang, or may expect you to write in proper English.
Type in sentence case. Starting a sentence off with a lower case letter may give the appearance that you don't care or were too rushed to write properly. All caps is equivalent to email-yelling at the other person.
Create a subject line. Avoid leaving this space blank. Use it to reintroduce yourself and let the reader know who the email is from. Someone you've just met may not know your address and may not open the message. Clue the new acquaintance in from the start with a subject line such as "Message from John Smith" or "Greetings from your new co-worker."
Fill the body of the email with a brief paragraph that describes your experience meeting the other person and the reason for the email. For example, if you're writing to a new potential friend say something such as, "I enjoyed getting to talk to you at the party last night. Thanks for giving me your email address to keep in touch. We should get together and see a movie soon."
Use emoticons wisely. If you're writing to a new friend or potential romantic partner, a sweet smiley face is appropriate. Wait to use kissing faces or hearts with a potential relationship mate until you get to know him better. If you're emailing a new boss or other business acquaintances, hold back on using the emoticons.
Sign your email in a way that fits who the reader is. If you're emailing a new friend, try something such as, "Talk to you soon, Emily." If the reader is someone in a more formal position, keep the end of the email more straight-laced and simple, opting for a sign-off such as "Regards, Joe Smith" or "Thank you, Tim Web."