re: I have my Thunderbird settings set to Leave message on server. I have a POP account setup that I access on two different PCs. When I delete an incoming e-mail from my Thunderbird client it deletes the e-mail from the server. these are two different settings. The ''' Leave message on server '''setting refers to what to do when you download from the Inbox - to leave a copy in the inbox on the server. when you delete an email there maybe a setting to remove the email from the server, if it has been deleted in Thunderbird You will need to check this on both computers, because if one computer leaves it on the server and the other doesn't it will explain removal. * Tools > Account Settings > Server Settings for the pop mail account * Select: 'Leave messages on the server' Have you got any of these selected? * 'for at most xx days' if yes, this will remove all emails older than the number of days selected. * 'Until I delete them' if yes, then this will remove the deleted email from the server. deselect so the do not have a check in the box click on OK to save changes