MERCUR stores all the necessary information inside the MERCUR directory unless you installed MERCUR using a different directory name or structure, all you require to do is copy the entire MERCUR directory. There are three (3) primary subdirectories that should be backed up on a daily or weekly basis:
The CONFIG folder contains all the user data. The MAIL folder contains the mailboxes of all user accounts. The LOG folder contains the log files for all MERCUR services.