Examples of Exchange Online features that are available to enable include:
Disclaimers. Exchange Online enables administrators add disclaimers to messages in transit using transport rules. See the Help topic Add Disclaimers to Messages for details.
Transport rules. Transport rules are used to inspect emails in transit (including inbound, outbound, and internal messages) and take actions, such as applying a disclaimer, blocking messages, or sending a blind carbon copy to a mailbox for supervisory review. See the Help topic Organization-Wide Rules for details.
Personal archive. Exchange Online offers archiving through the personal archive capabilities of Exchange 2010. A personal archive is a specialized mailbox that appears alongside users’ primary mailbox folders in Outlook or Outlook Web App. See the Help topic Enable an Archive Mailbox for details.
Journaling. Administrators can configure Exchange Online to journal copies of emails to any external archive that can receive messages via SMTP. See the Help topic Journal Rules for details.
Retention policies. Exchange Online offers retention policies to help organizations reduce the liabilities associated with email and other communications. With these policies, administrators can apply retention settings to specific folders in users’ inboxes. The retention policy capabilities offered in Exchange Online are the same as those offered in Exchange Server 2010 Service Pack 1. See the Help topic Set Up and Manage Retention Policies in Exchange Online for details.
Legal hold. Exchange Online provides legal hold capabilities to preserve users’ deleted and edited mailbox items (including email messages, appointments, and tasks) from both their primary mailboxes and personal archives. See the Help topic Put a Mailbox on Litigation Hold for details.
Rolling legal hold (single item recovery). Some organizations want to preserve users’ mailbox contents for archiving and eDiscovery purposes, but only for a specific amount of time, such as one year. The single item recovery feature in Exchange Online can be used to meet this need, by providing rolling legal hold capabilities.
Multi-mailbox search. Exchange Online provides a web-based interface for searching the contents of mailboxes in an organization. Through the Exchange Control Panel, administrators can search a variety of mailbox items—including email messages, attachments, calendar appointments, tasks, and contacts. See the Help topic Create a New Multi-Mailbox Search for details.