SCOT and RFC problems

Hello all,

I swapped R/3 4.6C server past saturday and now I have a problem regarding sending e-mails.

To send e-mails, server is using a external smtp. When I try to test connection in SM59 and response is :

+ERROR                program LU-HUB000/LU/Server/PwC not registered+
 +LOCATION             SAP-Gateway on host LUDBS062 / sapgw00+        
 +DETAIL               TP LU-HUB000/LU/Server/PwC not registered+     
 +COMPONENT            SAP-Gateway+                                   
 +COUNTER              444+                                           
 +MODULE               gwr3cpic.c+                                    
 +LINE                 1593+                                          
 +RETURN CODE          679+                                           
 +SUBRC                    0+                                         
 +RELEASE              46D+                                           
 +TIME                 Mon Mar 30 16:45:21 2009+                      
 +VERSION              2+

I don't really understand the problem. Do I have to modify something directly at OS level ?

Thanks a lot for your help