automatic resignation???

This is the second time that I have left a correspondence game against the computer and come back to find that I have been subject to automatic resignation. My understanding is that a game with no time control can last indefinitely? Is that not the case? Is it not possible to log off and them resume the game ? Any help would be appreciated - regards Robbie

When I try to setup a correspondence game against the computer I can't chose unlimited time. How do you set this game up?