At some point, your users will delete an email that they need to recover. Exchange has the ability for end users to recover their own messages, but the administrator first needs to set up a retention policy. This can be set in the Exchange Server Administration Center.
You can either set retention policies globally for all of your mailbox users, or you can set policies for individual users. Since most users will need to recover an accidentally deleted email, it’s best to give all users at least some retention in case of an error. Although it takes up more space on your email server, it gives users a safety net should they delete a message and need it recovered.
Global Retention Policy
Open the Exchange 2016 Administration Center and click the database name for your email database. Under the name, you’ll see a link to “Limits.” Click this link.
In the section labeled “Keep deleted items for (days):” enter a number of days. Remember that users need several days to recover emails. Your users might not realize that they accidentally deleted an email for a couple of weeks. At the same time, you must remember that storing email for several months could take up a large chunk of your storage space. Most administrators allow a user to save deleted emails from 14-30 days, so they have within a month to figure out if they need a deleted email.
You can also use PowerShell to set retention policies. The following PowerShell command sets the ExchangeDb to a 14-day retention policy.
Set-MailboxDatabase -Identity ExchangeDb -DeletedItemRetention 14
Setting Retention Policies on Individual Mailboxes
Individual mailbox setups are also done in the Exchange 2016 Administration Center. Click through to the individual user’s mailbox and click the “Mailbox Usage” link.
In the section labeled “Customize the retention settings for this mailbox, Keep deleted items for (days)”, type the number of days you want to allow deleted messages to save. Just like global policies, the number of days should be at least two weeks but these messages also take up storage space. If you only allow certain individuals to store messages, then you can be more generous with the days.
You can also use PowerShell to set retention policies. The following command sets a retention policy for 14 days for the user “John Smith.”
Set-Mailbox -Identity “John Smith” -RetainDeletedItemsFor 14 -UseDatabaseRetentionDefaults $false
Recovering Emails in Outlook
Once the policy is set, your users can recover deleted emails from their Outlook mailboxes. Under the mailbox name, the user just needs to click on the “Deleted Items” link to view a list of deleted emails. Right click the folder and select “Recover Deleted Items.” The user can also recover individual emails by right-clicking a deleted item and selecting “Restore.” The message is then moved to the user’s inbox.
Exchange 2016 makes it easy for administrators and users to recover deleted messages. Once a policy is set, your users can delete and recover as needed.