when you you hit the Send/Receive (Get Mail) button?
What email client is she using?
What version of OS X is she using?
Are there any little icons on the end of the Mailbox name in whatever mail client she is using?
Does the missing mail show up when she accesses the webmail of whatever ISP she is using?
My mother's inbox has been empty for several days. She usually gets messages from friends and the ny times. I tested yesterday sending an article from the ny times and my gmail account to her inbox from her computer and it went through. From my computer I forwarded some times articles and also reset her times password. According to gmail they were sent. When I checked her inbox today it was empty and she hadn't checked her email for 2 days. Is there some problem with her email and if so what should I look for?