hey, it works ;) the problem was the synchronisation of password. I 
changed it, went to the UnlockChapta Link. And that's it!

Big Thanx to everyone for your support.

Colin Palmer wrote:
> On Mon, 2008-07-14 at 11:53 +1200, Ivo Senner wrote:
>   
>> So this is my first question: I've tried to setup an imap account for

>> my university address at thunderbird. But everytime I trying to
>> connect to imap.gmail.com i get the message "Invalid credentials
>> (Failure)". While searching in google for a solution I can only find

>> the notice to activate IMAP at webmail. That was the first thing i've
>> done. Does anyone know something about this behaviour? or how to setup
>> the imap-account correctly?

>>     
>
> The ITS service desk are the best people to ask about this, since some
> of the details are UoW specific.  However most of what you need to know
> is here: http://mail.google.com/support/bin/answer.py?answer=77662

>
> Things to note:
>
> - SSL/port 993 is compulsory, standard IMAP won't work.
> - Your IMAP username is <user>@students.waikato.ac.nz

> - Your password should be the same as your UoW one, but may not be
> sychronised, especially if you've never used
> https://tools.its.waikato.ac.nz/cgi-bin/changepw so go there and set a

> new password.
> - It's easy to lock yourself out by entering the wrong password too many
> times, so you may need to visit
> https://www.google.com/a/students.waikato.ac.nz/UnlockCaptcha before

> trying again.  This will confirm the new password you just set works.
>
>