I just realized that in Ubuntu 11.10 fresh install the message indicator menu doesn't notify me if I have new mail, just in case of starting Thunderbird. The email setup completed, when Thunderbird is running and downloading new email, the indicator works well.
But, when Thunderbird is not running, i thought the indicator checks for new email in the background without i need to start Thunderbird manually.
Checking for new emails is set for 1 minute period under settings menu (Thunderbird).
Is there something that i need to set for that checking period also applied for the indicator menu, or i'm missing something during the program setup, or is this a known bug?

Thanks in advance!