Added waiting time before closing connection.

go-sendxmpp.go

@@ -13,6 +13,7 @@ import (
 	"os/user"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/mattn/go-xmpp"                // BSD-3-Clause
 	"github.com/pborman/getopt/v2"            // BSD-3-Clause
@@ -352,6 +353,10 @@ func main() {
 		}
 	}
 
+	// Wait for a short time as some messages are not delievered by the server
+	// if the connection is closed immediately after sending a message.
+	time.Sleep(100 * time.Millisecond)
+
 	// Close XMPP connection
 	err = client.Close()
 	if err != nil {