Got below error message when using proxy.eu.jabber.org as xmpp proxy server for XEP-0065. Is this a public proxy server so everyone can use? The error message shows "service-unavailable". That's why I am wondering whether "proxy.eu.jabberd.org" can be used in my case. Thanks!
RECV: <iq xmlns="jabber:client"
from="proxy.eu.jabber.org" to="xxx@xxxx.xxxx.com/41116223421355205171673791"
type="error" id="4B181DA2-B99B-471F-82FD-1BC8D463002A">
<error code="503" type="cancel">
<service-unavailable xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/>
</error></iq>