To back up Exchange data, you can select the following:
Symantec recommends that you select individual storage groups for backup rather than selecting individual databases in storage groups. Although you can select individual databases in a storage group for backup, the transaction logs for the entire storage group are backed up for each database selected.
For example, if you select four databases in a storage group for backup, the entire collection of transaction logs for the storage group is also backed up four times. The transaction logs are not deleted until a full backup is run on every database in the storage group. You can still restore an individual database from a storage group backup.
To perform incremental and differential backups of storage groups, or to perform a backup job for which continuous protection is enabled, make sure that circular logging is not enabled on the storage group.
See Backing up Exchange.