Yes, the data you store online through your use of BCP services is backed up.
Your E-Mail Mailbox
The University's Standard Practice Guide (SPG 601.8-1) states that system administrators will, "Back up electronic mail for the purpose of disaster recovery (catastrophic system failure) only. Back-up periods should be as long as needed for full restore but preferably no more than one week and shorter if possible."
Therefore, ITCS backs up e-mail mailboxes for disaster recovery only and keeps the backups for no more than one week.