I have my Verizon e-mail account synchronized with my Toshiba Thrive. I'm using outlook express as my e-mail program on my desktop. The e-mails will display on both the Thrive and the desktop but I cannot delete e-mails from the Thrive. I have on 2 occasions deleted all e-mails from the Thrive but both times they have reappeared. How can this be corrected?