Why I can't configure a gmail account on Windows Mobile 6.5

[Windows Central Question]

Sorry for adding this question here, but there is no place to add questions about windows 6.5 (on Getac PS336). I entered E-mail and then clicked on Setup E-mail. I entered my gmail address, and my account was automatically configured. But now I can't send nor download any messages because I get a notification "Messages cannot be downloaded to your mobile device. Make sure you are connected and that your e-mail account settings are correct. Then, try to download messages again." I'm 100% sure that I entered correct gmail address and password.

What should I do to configure my account?

Thanks,
Tomasz