Symantec Messaging Gateway (SMG) appears to be trying to do a file system scan (fsck command) and it is failing and asking for a root password to continue.
*** An error occurred during the file system check.
*** Dropping you to a shell: the system will reboot
*** when you leave the shell.
Give root password for maintainance
(or type Control-D to continue):
The filesystem of the SMG has become damaged and the built-in file check software cannot repair the file system.
This error will require a reinstallation of the SMG software from ISO, and a restore from backup. Messaging Gateway has no root password.