Perform the following troubleshooting steps:

Check that your email settings are correct (consult with your email service provider). Go to the Home screen and select Accounts > your mailbox > Incoming email server and check settings. Also check the settings of the Outgoing email server.

Next troubleshoot your access point:

  1. Check the network quality on your device.
  2. Check that you are using the proper access point. You should use the access point that enables you to access websites using the Internet, don't use WAP.
  3. Try to connect to the email server by using different types of connections (3G - WLAN etc..) in order to guarantee a successful access to your email.
  4. Also check that other applications are working on the same Internet Access Point.

If the above does not help try the following steps:

  1. Remove the mailbox from your device.
  2. Restart your device.
  3. Try to define a new mailbox again.
  4. If that does not help, then reset your device to factory settings: On the Home screen select Settings > Reset phone. The lock code is needed, if you have protected your device by lock code. After reboot define your mailbox again.