External Component unable to send a message within the same xmpp domain (federation)

Hello everobody,

I have developed an external component using Whack API and try to test it in a tiny federation of two xmpp servers that share the same domain. Their addresses are talk1.domain.com and talk2.domain.com, accordingly.

The issue I am expereincing is that when I bind my external component to “abc.talk2.domain.com” and try to send a message to somebody like "jid@talk1.domain.com", I keep receiving this:

Is this an XEP level restriction? It seems strange that while users from talk1 and talk2 can easily communicate with each other, such a capability is prohibited to external components.