fix for #129011. movemail can support filters. r/sr=sspitzer. thanks to pretzalz@techhouse.org for the fix.

mailnews/local/src/nsMovemailIncomingServer.cpp

@@ -71,6 +71,7 @@ NS_IMPL_ISUPPORTS_INHERITED2(nsMovemailIncomingServer,
 nsMovemailIncomingServer::nsMovemailIncomingServer()
 {    
   NS_INIT_ISUPPORTS();
+  m_canHaveFilters = PR_TRUE;
 }
 
 nsMovemailIncomingServer::~nsMovemailIncomingServer()