12:57:33,860 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) WFLYCTL0013: Operation ("add") failed - address: ([
    ("socket-binding-group" => "standard-sockets"),
    ("remote-destination-outbound-socket-binding" => "mail-snmt")
]) - failure description: "WFLYCTL0212: Duplicate resource [
    (\"socket-binding-group\" => \"standard-sockets\"),
    (\"remote-destination-outbound-socket-binding\" => \"mail-snmt\")
]"
12:57:33,863 FATAL [org.jboss.as.server] (Controller Boot Thread) WFLYSRV0056: Server boot has failed in an unrecoverable manner; exiting. See previous messages for details. - Server configuration file in use: standalone.xml

wildfly-configuration:
    socket-binding-group:
        standard-sockets:
          remote-destination-outbound-socket-binding:
            mail-snmt:  
              host: foo
              port: 8081
            foo2:
              host: foo2
              port: 8082

wildfly-configuration:
  socket-binding-group:
    standard-sockets:
      remote-destination-outbound-socket-binding:
        mail-snmt:
          host: foo-override
          port: 8083
        foo2:
          host: foo2-override
          port: 8084