Message Recycle Bin
(un-delete)

The ESI phone system stores up to 10 of your most recently deleted messages in a Message Recycle Bin to allow you to recover, or “un-delete,” messages that may have been deleted in error.

You access the Message Recycle Bin through user programming (PROGRAM 9).
Press 9 to advance through deleted messages. Press 8 to restore a message to your mailbox as an old message.