Openfire currently does not include a 'to' attribute in stream stanzas that it sends when initiating a new S2S connection.
RFC 6120 section 4.7.1 reads:
For initial stream headers in server-to-server communication, the 'from' attribute is one of the configured FQDNs of the server, i.e., a JID of the form <domainpart>.
A 'to' attribute should be included.
The outgoing server session stream now got the attribute. It's value is the local domain name.
Maybe good to link with !