When your gmail keeps showing you the error in downloading the messages. It means, your message box is full. that's why Gmail is unable to download the new messages. in such a case, you need to remove the current account from the aol mail and then re-add it using the valid mail settings. it will start working fine for you then. 1. Check the storage on the gmail. 2. Delete some messages. 3. Refresh the mailbox. 4. Check the Pop3 server configurations. now reboot the computer again. it will start working for you. if it doesn't work, you need to visit: gmail error too many messages to download