E-mail Account Quota exceeded! Unable to add “XXXX”
This error is caused by an insufficient number of mail-level licences for the CyberSecure backup service account.
If the entire Exchange store has been selected, then every mailbox in the store will be backed up, which could mean mailboxes created after the backup was initially setup.
More Exchange mail-level licences are required to be purchased under the account: equal to or greater than the number of mailboxes attempting to be protected.
To backup only specific mailboxes, simply select the individual mailboxes in the backup configuration, rather than the entire store.