OWA - Retention Polices
Retention policies are part of messaging records management technology available with Microsoft Exchange Server 2013 accounts. This makes it easier to keep messages that are needed to comply with organization policy, government regulations, or legal needs, and to remove content that no longer has legal or business value.
Assign a retention policy to an email folder
Right click a mail folder.
Click Assign Policy.
Click an entry based on your organization’s guidelines.
Assign a retention policy to an email message
In the message list, right click a message.
Tip: To select more than one message, press and hold CTRL as you click each message.
Click Assign Policy.
Click an entry based on your organization’s guidelines.