The value of the 'to' attribute provided by the initiating entity in the stream header does not correspond to a hostname that is hosted by the server.
After upgrading from 0.16 beta2 to rc1 I get the following error connection to a prosody0.10 server: The value of the 'to' attribute provided by the initiating entity in the stream header does not correspond to a hostname that is hosted by the server. The server is running a virtualhost foobar.tld, but is really running on xmpp.foobar.tld. SRV-records for foobar.tld exist and point to xmpp.foobar.tld. The domain foobar.tld itself points to another host.
I'm not really sure if it is an issue of prosody or gajim.