Users' IM conversations and all associated file attachments are archived on the Conversation Store page. Conversations are organized and can be sorted (click on column heading to sort order) by: date/time, participants, size (bytes), and filename.
Note: If, on the General dialog page, the number of days has not been set to at least one day, the server will not store any conversations. And, if the server does not log messages, Full Context Messaging is not possible.