To transmit your resume via e-mail, save it as a plain text document. Do not attach a word-processed version of your resume to an email message. Instead, play it safe and paste it into the e-mail. Unless you are instructed otherwise, include a cover letter. Send your resume and cover letter embedded in one e-mail message. View our sample electronic resume and consider the following additional tips:

In lieu of boldface, underscoring, or bullets which cannot be used in a text document, substitute asterisks (*) or plus signs (+), and capital letters, to highlight text. 

Use a series of dashes to separate headings. 
Keep lines at about 65 characters to avoid line wraps. 
Scanner Tips for Resumes Forwarded Via Mail or Fax

Use popular, non-decorative typefaces. 
Use a font size or 10 to 14 points, and don't compress spaces between letters. 

Use white, standard size 8 ½" X 11" paper printed on one side only. 
Avoid italic text, script, and underlined passages or tab indents. 
Avoid graphics, shading and boxes. 

Place your name as the first readable item on each page. 
Use keywords to maximize your chances of being selected by the organization's "electronic eye". You will need to present on your resume a mix of keywords and skills that match various position requirements included in the employer database. 

Adopted from:
http://www.careercenter.sjsu.edu