1. This is a possible corruption of the pop3uidl file. Close the Internet connection and all programs. Search for the file ‘pop3uidl and delete it. Reconnect and it should work
  2. Repeat step 1 with a reboot before you check your mail again
  3. You may have a corrupt or a very large file attachment on the mail server. Large file attachments, mail that are missing headers or mail that do not conform to the mail RFC’s can cause this
  4. Outlook Express Error : 0x800CCC0B SERVER OR MAILDROP IS BUSY
  5. Try to retrieve e-mail about once every 5 minutes. Alternatively, call your ISP help desk to make sure that the server hasn’t crashed
  6. You may be logged in on another machine. Close all connections on all machines, wait 20-30 minutes and then try again
  7. Some mail servers will not recognise an improper disconnection. This will result in the account being ‘Poplocked’. Either wait 20-30 minutes for it to time out or get somebody to shell into the mail server and stop the mail task that is running on the account. This can normally only be done with accounts that have UNIX shells
  8. If you are not logged in on another machine or poplocked then someone may be using/downloading from your account or something is wrong with your account