TMG block inbound mail traffic

Hi, am setting up TMG for exchange 2010 and have published the rule based on 

http://technet.microsoft.com/en-us/library/dd441082.aspx

Now am getting error that "TMG Denied SMTP via Default rule"

Have check articles pertaining to this and still have got no clue what could be wrong.

Did an exchange test analyzer and it fails connection rejected from destination.

Any advice appreciated.