I have found out some more about this problem. This morning I couldn't get into the webmail on Firefox for my ntlworld account, it kept saying a connection error. I then tried on Thunderbird and it all worked ok and I was able to download emails. I then contacted Virgin Media and while on the line I suddenly thought of trying the webmail on Chrome and it worked ok on there so I then thought there might be a cookie problem on Firefox so I cleared all the Virgin Media cookies and the webmail worked ok then. I then put some emails back in the inbox on the webmail that I had removed to see if there was a corrupted email and tried to download them to Thunderbird and they wouldn't download. I then thought I would close the webmail tab on Firefox to see if they would download and they did! The webmail was still open on Chrome. So it seems to be a Firefox problem not letting me download these emails. Does anyone have any ideas on this?