This e-mail is for contacting a potential employer to whom you have recently sent or e-mailed a resume. It's a good idea to make sure your resume was received, and to refresh the employer's mind about you.
I'm just checking to see if you received the resume I sent <time resume was sent> in response to your ad in the <name of publication or Web site>. I know you've probably been inundated with resumes, and I want to make sure that mine doesn't fall through the cracks. If you have time, please drop me a quick reply and let me know if you received my information, and when you might be conducting interviews. I'm eager to find out more about the possibility of working with your <company name>. Thanks for your time. I look forward to hearing from you.