If you're submitting your resume on a popular job board like Monster or Careerbuilder, the sites generally ask you to paste your résumé into a blank field. You've been understandably thoughtful in your résumé's formatting, with every bulletpoint just-so, but unfortunately your gorgeous résumé landscape doesn't usually translate when you copy and paste. Similarly, some employers will specify 'no attachments' in their job listings, which really does mean no attachments — follow directions from the start if you want the job! These employers know what they want, and what they want is your resume in the body of an email. Which means no fancy alignment or spacing. That doesn't mean you should ditch that pretty résumé you're so proud of, it just means you need to create another version to have on hand for these instances. Discover what steps to take when you

The folks over at Careerbuilder must have been going bonkers over the number of jumbled résumés they've been receiving, because they laid out clear as can be details for making your résumé e-friendly [1]. Here's their breakdown.

1. Remove all formatting from your original résumé. Removing it will allow the computer to understand what you're asking it to process. To remove the formatting, open your word-processed résumé and choose the "Save As" option under the "File" tab on your toolbar. Save the document type as Plain Text or Text Only. In the following dialog box, choose the option to insert line breaks.
2. Use Notepad, WordPad or SimpleText to reformat. Close your original résumé document and re-open the text version using Notepad, WordPad or SimpleText. Your text version should be free of most graphic elements, like fancy fonts, lines and bullets. Text should be flush with the left side of the document.
3. Stick to a simple font and style. Use clear, sans-serif fonts, like Courier, Arial or Helvetica. This way, the computer won't mistake your fancy lettering for a jumbled word. Use a 12-point font; anything smaller won't scan well. Also, stay away from italics or underlining. Rather than using boldface type, try using capital letters to separate sections like education and experience. Instead of using bullets, use such standard keyboard characters as an asterisk or a dash. Instead of using the "Tab" key, use the space key to indent. Make sure all headings -- like your name, address, phone and e-mail -- all appear on separate lines, with a blank line before and after.
4. Apply keywords.Applicant-tracking systems scan résumés for keywords that match the company's job descriptions. Fill your résumé accordingly with such words (as they pertain to your experience), but remember that using the same word five times won't increase your chances of getting called in for an interview. avoid abbreviations as best you can. Spell out phrases like, "bachelor of science" or "master of business administration."
5. Test it out. After you've re-formatted your résumé into a text document, make sure it really is e-friendly. Practice sending your new résumé via e-mail to yourself, as well as friends who use a different Internet service provider.

Source [2]