To change the expiration date of a message go to File-Get Info. If you do not change the expiration date mailbox messages automatically expire in 59 days. Conference messages automatically expire in 180 days. First Class has a wide variety of mail forms available. All of the forms can be access by going to the File menu, pulling down to New and selecting the form from the submenu.
Some forms are only available to specific users, such as site moderators.
You must have the most recent setting file on both the sending and receiving machines for the forms to work.