Each FirstClass object has a default expiry period. After this period is up, FirstClass keeps the object for a waiting period that is set by your administrator, and then deletes it. You can change this expiry period.
Some objects, such as documents and objects in folders, never expire by default.
To change the expiry period, open the object's properties, then update the expiry information on the Info form.
If you change the expiry period on the Info form before you send a message to a conference, the message will obey your specified expiry period rather than the conference's default expiry period.