I have a common mailbox where the messages have to be cleared which are older than 30 days.
Note : This feature requires an Enterprise Client Access License.
Login to EAC (Exchange Admin Center) – Compliance Management – Retention Tags – Click on 1 month Delete.
We are specifying
Delete and Allow recovery – Moving to dumpster then it stays in the dumpster for the retention period specified on the database. if there is a retention specified on the mailbox it takes precedence.
If you choose Permanently delete it never gets moved to dumpster – Non recoverable. We are specifying the item reaching the age of 30 will get archived.
Compliance Management – Retention Policies – Add the retention tag we created “Click on 1 month Delete”
Choose save
Now apply the Retention Policy on the mailbox
Recipients mailboxes – Mailbox Features – Retention Policy (Choose the policy we created)
Choose save.
Now any Items which are older than 30 days will be archived in the common mailbox.
 – Compliance Management – Retention Tags – Click on 1 month Delete.){kind=link}