[Standards-JIG] Syntax for forwarding messages

Stephen Marquard scm at marquard.net
Sun Jan 2 17:48:37 UTC 2005


Is there any current mechanism to indicate the original sender of a 
forwarded message? (e.g. similar to email Sender: or Resent-from:).

I see this was raised in a previous thread without resolution:


JEPs 62 and 63 look nice but don't cover how a forwarded message would 
be formatted. JEP 33 doesn't seem to cover it, and JEP 131 seems a bit 
over the top, as well as requiring service discovery before use.

Consider this example:

1. user1 at serverA sends a message to serverB (just the domain name).

2. serverB is configured to forward messages to its plain JID to 
user2 at serverC.

3. So serverB can format the message as:

<message from='user1 at serverA' to='user2 at serverC'>

which is not going to get through the s2s connection from serverB to 
serverC, c/f XMPP 8.3: "Furthermore, a server MUST verify that the 
'from' attribute of stanzas received from the other server includes a 
validated domain for the stream; if a stanza does not meet this 
restriction, the server that receives the stanza MUST generate an 
<invalid-from/> stream error condition and terminate both the XML stream 
and the underlying TCP connection."

or format it as

<message from='serverB' to='user2 at serverC'>

which doesn't let user2 know who sent the original message.

A similar problem would apply to a user on serverB who wished incoming 
messages to his/her JID to be forwarded to a JID on another server.

A simple solution would be something like:

<message from='serverB' sender='user1 at serverA' to='user2 at serverC'>

but would this be legal XMPP ?


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