MS Exchange 5.5 does not route email

We are running Exchange 5.5 on Small Business Server and cannot get email routed to the mailboxes. When we reboot the server, it goes online and redirects ‘some’ email but not all. The server then carries on running but MTA falls over and will not restart as a service.

Microsoft have asked us to run ESEUTIL.exe as a command line utility. Apparently this is a utility that performs an offline defrag and repair of databases. However, when I try to run it, it reports that it cannot find the database with the email information that it is trying to defrag.

Can anyone help?