Postbox has detected a problem with your Gmail account that is preventing it from logging in.
- Make sure that you've entered your full email address (e.g. email@example.com)
- Re-enter your password to ensure that it's correct. Keep in mind that passwords are case-sensitive.
- Make sure your mail client isn't set to check for new mail too often. If your mail client checks for new messages more than once every 10 minutes, your client might repeatedly request your username and password.
After checking those settings, you may need to unlock your Google account. To unlock your Google account:
- Quit Postbox and then visit https://www.google.com/accounts/DisplayUnlockCaptcha
To unlock your Google Apps For Your Domain account:
- Quit Postbox and then visit https://www.google.com/a/YOURDOMAIN.COM/UnlockCaptcha (substituting YOURDOMAIN.COM with your hosted domain name)
Helpful links at Google