When migrating mailboxes you may see a Transient error StorageTransientException has occurred, this is because the mailbox is poisoned and quarantined.
When migrating mailboxes in various versions of Exchange you see this error Active directory response: 00002098: SecErr: DSID-03150A45, problem 4003 (INSUFF_ACCESS_RIGHTS).
When trying to add your DAG node to backup exec you see the following error. The Backup Exec Remote Agent Must Be Installed And Running On All Nodes In The Dag
When sending emails to certain domains to youget an error stating #450 4.7.1 Client Host Rejected Cannot Find Your Hostname ##. This is a reverse lookup error.