re:''when people send e-mail to me it bounces'' Emails sent to your email address are not getting through and the sender is receiving a bounced back Mailor Daemon response. So, you are not even receiving emails into your webmail account. Thunderbird cannot download something that is not there. You mention you use POP. It is usual for pop mail accounts to download from server Inbox to mail account Inbox in thunderbird and then delete the email off the server. However, there is a setting in Thunderbird Account Settings > Server Settings to 'Leave messages on server'. I'm presuming this is how you have set this up. This means that there could be a load of emails left in the server Inbox and you have used up your server quota, so it cannot receive any more mail. Suggest you logon to your webmail account and delete the emails. Check any other folders on the server such as 'Spam' and empty that as well. As Thunderbird is the only place you have stored emails, please remember to create a backup of your profile folder. * http://kb.mozillazine.org/Profile_backup