Messaging Records Management, otherwise referred to as MRM, is the archiving tool admins can use to manage records within Exchange. While some features are moving around between different admin centers, most of our time today will be spent within Microsoft Purview. But before we get into that, let's talk about the main parts of Messaging Records Management. Starting off, we need to cover retention policies. Retention policies are used to determine how organizations retain content within their environment. These policies can be created and configured to allow varied retention based on whatever content they are retaining. Retention policies are available for use across Microsoft 365 with SharePoint, OneDrive, Teams, Yammer, but today we're going to focus specifically on Exchange. Within Exchange, these policies determine how to retain content using sets of retention tags, and these retention tags come in three different varieties: default policy tags, retention policy tags, and personal tags. Default policy tags are pretty much what they sound like, the default retention tags.

Default policy tags effectively apply to an entire mailbox, however, the items within the mailbox are only tagged with the default policy tag if they aren't already tagged with another retention tag. Effectively, anything within a mailbox that isn't tagged, automatically gets tagged with the default policy tag. The retention policy tags, on the other hand, take precedence over the default policy tags and can automatically apply to default folders within mailboxes. These are folders that are automatically created within mailboxes, such as the Inbox, the Deleted Items folders, and they don't include personal folders that the user may have created. For those custom-made folders, we have personal tags. Personal tags are the only tag that users can apply themselves, as both the default policy tags and retention policy tags are specifically assigned by administrators.

Users can manually apply their personal tags to items and custom folders within their mailboxes. But now that we understand how retention policies work within Exchange, let's take a look at my demo mailbox and showcase where and how the tags work. Starting off, the default policy tag. This entire mailbox is tagged with the default policy tags, as even though other tags take precedence, default policy tags technically apply to every mailbox within that environment. If a retention policy has been applied to this mailbox, however, the retention policy tags would then take precedence over the default policy tags, meaning that the default folders all have the retention policy tags applied to them. But since the Custom Folder was created by the user, this is instead managed by personal tags that the user can assign manually. Remember, when default policy tags are assigned, if anything within this mailbox is not tagged by another tag, then it will technically fall under that default policy tag.