The users is in the JAMESUSER table.

Depending on your virtualHosting config, JAMESUSER.NAME is the email address (or the user part that must be completed with a domain).

The user has MAILBOXes via the SUBSCRIPTION table.

The email are in MESSAGE (belonging to a MAILBOX via MEMBERSHIP). You have to look in the HEADER table to get all the detailed information (from, to, cc, bcc,...).