Many candidates would not respond in a timely manner and others would have questions on how to do.

Emailing candidates back and forth to tell them to resend the application is not a productive practice. Recruiting for roughly 50 open positions with job advertisements on many different sites I naturally get bombarded with emails many of which I could not open properly. Working as a recruiter I have only had the privilege to work in windows based offices, even though I am a mac user primarily.