e-mail disclaimer on Exchange 5.5 sp4

I have tried to implement disclaimer on outgoing e-mail. I have done the following:
1 – copied imsext.dll to exchsrvr\connect\msexcimc\bin
2 – at command prompt ran – regsvr32 imsext.dll (successfully registered).
3 – edit registry – Added valuehklm\system\currentControSet\Services\MSExchangeIMC – added value NonRoutingExtensionDll datatype REG_SZ, String value c:\exchsrvr\connect\msexcimc\bin\imsext.dll
4 – created key in registry – hklm\system\CurrentControlSet\Services\MSExchangeIMC -added key Extension
5 – added value to registry – hklm\system\currentcontrolset\services\msexchangeimc\parameters – added name OutboundAppend, Datatype REG_SZ, String Value (the message to append to the e-mail).

This is still not working. Any suggestions?