If you are able to login using a web browser but your mobile device or email client does not accept your password/passphrase, you can try the following.
First, log in using the web client: http://www.uni.edu/email .
- Once you can see your inbox, visit http://www.google.com/accounts/DisplayUnlockCaptcha  with the same web browser without logging out. If necessary, enter the letters in the distorted CAPTCHA picture.
- Click Continue.
- Restart your mail client and try accessing messages in your email client again.
For Google's full article on this topic follow this url: