During a past job search, a recruiter added her company name as my résumé's header. When viewed in Word the header was hidden, but as a printed page her name was there in bold, leaving me susceptible to making a serious mistake when applying for jobs outside the efforts of my recruiter.
Employers often print out résumés even if it was sent through email, especially if you're scheduled to interview. Before sending your résume print it out to check for big mistakes like the one I described. Make sure your formatting is intact, and take the time to triple check for any grammatical errors that wouldn't have been caught by spellcheck (like mistakenly using their for they're).