If your SAP system is already been configured for Message Server than you to do some changes in below file.
1. JAVABE.ini file - > Change logon method to GroupLogon and pass the details of your message server.
2. Navigate to following path and edit Services file to add following entries.
"C:\Windows\System32\drivers\etc"
Things to add - Message server name with available tcp/ip port.
Hope this helps you.
Ajitesh