eMail messages not downloading

My wife and I use AOL for our email service (formerly Verizon). My wife is using a POP3 account on eM Client to manage her email there. Back in mid-May her current email stopped downloading to eM Client. Then eM Client began downloading messages from several years ago that she had long ago deleted. Then eM Client stopped downloading messages at all. When I try to monitor the downloading of messages in Operations all I see is “listing messages”. At some point this process stops and the program reports that no Operations are in progress. The error message we get is:

"Connecting to her email address failed. An Attempt to connect to her email address failed. This could be caused by temporary server unavailability or incorrect settings. Do you want to check the settings?

The server is available. The settings are unchanged from when messages were downloading.

Does anyone have any suggestions about how to get her email messages to resume downloading?

Thanks.