Redmine

I have successfully set up my RedMine installation to Fetch mail from our mailserver via IMAP according to this tutorial:

http://lucisferre.net/2009/08/21/redmine-2b-imap-2b-gmail-3d-easy-ticket-submission-via-e-mail/

However i need anonymous users to send ticket submissions, as it is now only registered users email get fetched. Can someone help me?

I have several Projects but only one(Unsorted) is set as Public

My Rake call:
CALL rake redmine:email:receive_imap RAILS_ENV="production" host=xxx.xxx.xxx port=143 username=xxx password=xxx project=unsorted tracker=support allow_override=project,tracker,priority

Thanks for your input!