The telepathy-gabble-plus RPM available on your website doesn't have the chat marker functionality, I suppose it wasn't updated to reflect the latest changes in the source code.
Is it possible to provide an RPM for i486 architectures?
I was trying to test support, and I'm not sure if this should work or not.
I disabled all of my other jabber clients except for the one running your branch, I went to a different computer, prepared to send a message, pulled the ethernet cable from the test computer and in about 3-5 seconds sent the message from the other computer. I then reconnected the Ethernet cable and hoped to see the undelivered message.
Unfortunately I didn't seem to. I'm currently using kde-telepathy and haven't implemented any client side support.