Gmail account not accepted

[ubronan]

I use several gmail accounts some for catching spam others as main for certain tasks thats how i prevent being spammed to death.

I found this program and this far looks good but i have something very weird
One of my gmail accounts does not want to be added no matter what i do

I constant get non valid message when i want to add the account.

Now i can assure you it is an existing account and that all info is right but no matter what i do i can not get it added.