[asterisk-users] delivery verification of instant messages with pjsip

[hw]

Hi,

when sending IMs from endpoint to endpoint with the MessageSend() application, 
I can check the MESSAGE_SEND_STATUS and send another message to the sender of 
the message to notify them that their message was not sent when the status 
indicates it.

This works fine with chan_sip.  With chan_pjsip, this works differently in 
that MESSAGE_SEND_STATUS is "SUCCESS" after sending the message, and only 
later asterisk figures out that it is "Unable to retrieve contact for endpoint 
<xxx>" when there are no contacts and thus the message never gets delivered.

How can I check if the endpoint has contacts --- or preferably --- if the 
message was actually delivered to an endpoint?  It would be sufficient to get 
it to work with endpoints that are not supposed to have more than one contact.