Recently when setting up friends and customers with Google Apps I keep getting authentication errors. I try and log into there webmail and this works fine, it’s only when logging in via POP3 or IMAP I get this password problem. Upon investigation Google seems to be locking some accounts with Captcha To unlock your Google Apps Email account via captcha go to http://google.com/a/yourdomain.com/UnlockCaptcha ( Replacing yourdomain.com) with your actual domain name Enter the Username and Password and the Captcha code , once it gives you the green light that your account is unlocked , it will authenticate fine! Google , It would be nice if you can warn the user he/her account is locked in webmail at least!

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Also use this to turn on less secure Apps. e.g. Imap! https://www.google.com/settings/security/lesssecureapps