Comparison

mod_s2s: Enable outgoing Direct TLS connections Makes it faster by cutting out the roundtrips involved in <starttls/>, at the cost of making an additional SRV lookup. Since we already ignore a missing <starttls/> offer and try anyway there is not much difference in security. The fact that XMPP is used and the hostnames involved might still be visible until the future Encrypted ClientHello extension allows hiding those too.