Job lifespan on Easy Link switches

Hello,

API manual says in DocumentTransmit overview [https://apiforums.easylink.com/emapidocs/26/DocumentTransmit/DocumentTransmit.html] that documents are not kept on EasyLink switches indefinitely.

Q1: How exactly long documents are kept?
Q2: Can this be controlled from API?

Thank you in advance

Krzysztof