private void sendDialbackKey(String key) {
        StringBuilder sb = new StringBuilder();
        sb.append("<db:result");
        sb.append(" from=\"").append(domainPair.getLocal()).append("\"");
        sb.append(" to=\"").append(domainPair.getRemote()).append("\">");
        sb.append(key);
        sb.append("</db:result>");
        connection.deliverRawText(sb.toString());
    }
Sends the supplied dialback key to receiving server

@param key dialback key to send
xmppserver/src/main/java/org/jivesoftware/openfire/server/ServerDialback.java