Originally Posted by
paterwdb
Separate tickets on both domestic flights.
Your OP is correct except there is a train that can take you between the DL and EK terminals.
https://www.fly2houston.com/iah/inte...transportation
On the way back you may get lucky and have bag checked through on to UA but it doesn't really matter as you will have to claim them in IAH anyway and can drop them off in the transit area. Make sure to leave ample time to make the connection both ways.