My wife primarily uses her ipad using Apples mail app. I also have her email on my laptop (as backup) using Thunderbird. When someone sends and email to her. When she responds the reply displays in her Sent file on her ipad but doesn't on my backup account on my laptop (Thunderbird). If I reply to a message on her backup it displays in the sent file on Thunderbird, as it should Further, after 4 -5 hours the copy of the body of that email is replaced with the message "This message has not been downloaded from the server". I have deleted and recreated the email accounts on both devices. I have contacted both Apple and my ISP. They both confirm that everything is working properly. Please help.