You don't always get to apply for a job in person. Job postings often ask for email applications. Your qualifications and personality must stand out so prospective employers notice you. Be professional and to the point.
Type the name of the job posting in the subject line. For instance, if you are applying for a chemical engineering job, type "chemical engineer" in the subject line. Your email will stand out as the employer scans his inbox.
Begin with a professional salutation. If you know the name of the person you are emailing, use that; or begin with "Dear Sir or Madam."
Place your cover letter in the body of the e-mail. Make it short and to the point--two or three sentences that highlight your accomplishments and strengths.
Sign the email with a signature that includes all of your contact information: your home and mobile phone numbers, home address and email address.
Read through the entire email to look for errors. Do not trust spell checking to make sure that your grammar and spelling are correct. Be sure you've used the professional tone a job application requires.
Attach your resume to the email. Note that the resume is attached in the body of the email so the prospective employer doesn't miss it. A simple line such as "Please see resume, attached." will suffice.