The Internet is now one of the most popular places to search for jobs. Almost all major companies list their job openings on the Internet, either on their own website or through postings on Monster.com or CareerBuilder.com. According to "The Wall Street Journal," there were more than 4.7 million U.S. job postings on the Internet as of December 2010. This trend toward finding jobs on the Internet means that the job application process now begins with an email message rather than a cover letter, and there are different conventions associated with these two types of media.
Research the business you are applying to. The first step in the job application process is the same no matter how you are applying. Showing that you know something about the business is important to demonstrate that you really want the job, and gives you a chance to illustrate how you will be a good fit with the company.
Write your email message in a more formal style, but not as formal as a written cover letter. If you are applying for a professional or management-level position you will probably be including a more detailed cover letter as a separate file, so you want to keep your introductory email message brief and to the point. If you are not including a separate cover letter, the message should be somewhat longer and include brief references to your relevant education and background as well as your motivations for wanting the job.
Highlight how the skill set and experience you bring to this job will enable you to be exceptionally productive. Finding a productive employee is what hiring managers are really looking for, and making them believe that about you is key to getting an interview. Don't overdo it in your initial email message, but how you can help the company solve their problems/get work done should be the primary focus of your cover letter and in your interview.
Close the email with your full name, not just your first name or nickname. Also make sure to include both your telephone number and mailing address either as a header or a footer in your initial email message.
Include a specific reference to the job you are applying for in the body of your letter.
Send your initial email to a specific person: the head of department you are applying to, the company HR manager, for example. If you cannot find the name/email address of a specific person, direct your communication to the human resources department, not the general company mailbox.
Do not just cut and paste your resume at the end if your introductory email message. Most HR managers consider this lazy and unprofessional. The general expectation is that your resume and other supporting documents will be attached to the message as word-processing files in formats like Microsoft Office Word and PDF.