Postie just not working for me – help please

Tried installing it, looked good, but when i run Test Config I get no results. Run Postie – no results. I do get Unauthorised Post Attempt mails from the server.
Have deactivated and reactivated it. Uninstalled it and re-installed it.
Checke the support forums and helps but no useful advice found so far.
Can you help please.
I’ve followed the instructions closely and tried it with a gmail and an other new email address.

http://wordpress.org/extend/plugins/postie/