Managing Record Managent (MRM) in Exchange 2013

Managing Record Managent allows you to setup policies on how you wish to retain your messages - for example you can automatically discard all of your junk email items after 30 days and discard all of the Inbox folder items after 180 days.

MRM is comprised of:

Rentation tags: That simply state a duration of rentation, the scope (type) of rentation e.g. Default (that applies to entire mailbox) or Personal (that is applied by users) and the rentation action (what is performed to the mail e.g. discarded, archived and so on.)

Rentation Polices: Comprise of a number of rentation tags and are applied against a single (or multiple) user account.

In order to apply the rentation policy to the user you can use ECP:
Recipients >> Mailboxes >> User Mailbox Properties >> Mailbox Features amd then select the rentation policy from the list.

Or you can use EMS:

Set-Mailbox "Joe Bloggs" -RetentionPolicy "Default Rentation Policy"

Finally we can verify that the rentation policy has been applied:

Get-Mailbox "Joe Bloggs" | Select RetentionPolicy