Using centos 5.x, sendmail, as a server, downloading mail with thunderbird (although this happened with outlook too) every 5 or 6 months I open my mail client (thunderbird) and one of my mail accounts decides to download 1,000 or so mails from my server. Old mail that I had already downloaded before. I changed no settings and everything is the same as it was, but this happens enough, on all accounts, that it is just weird. It is like it gets to a certain size and then redownloads the same mails. And they are the same mails. I have had 'redownloads' of the same emails each time. I look in the queue, nothing there...same with the mailboxes in the user folders, var/spool/mail.... these mails are being held somewhere by centos, but I cannot find them...and they seem to want to all be downloaded again and again every 6 months.. what am I missing? thanks