In days of old people sent cover letters– pieces of parchment paper that were, in fact, clipped on top of their resume.
Sometimes people try to replicate that by attaching a second file with their resume to their emailed submission and naming it something like “cvrltr.doc” and expect the recipient to open the file and read it.
1. The first thing you need to do is not attach a separate file but, instead, use the message area of your email as a cover letter. No one opens a second file but if you place the exact same message in the body of an email, they will read it before opening your resume.
2. Use the cover email to make a case for how you fit the role that you understand to be open. You can do that in three paragraphs. The first paragraph explains why you submitted the resume (ad on a website; a recommendation from someone who works at the firm. Be specific and identify the job you understand is open)
The second paragraph summarizes how you fit the job (as I undertand it, you are looking for someone with x type of a background; I have x+y amount of experience doing exactly that for your direct competitor).
3. Ask for the interview. This is where most people err. They forget to ask for the meeting or fail to say something like, “Would you have time on Tuesday afternoon to discuss the position and my qualifications?”
Asking for the meeting is often a missing component of the cover email an, in many jobs will positively separate you from yo9ur competition.
Do these three things with every cover email you submit and you will create a great a great impression and a halo that will benefit you when you interview.