Hi ;
In occasional cases you may be needing to delete the mailbox content from an user;
In order to do so run the following from the Exchange Console /
Verify prior using the second command the items :
Get-MailboxFolderStatistics -Identity username@company.com | Select FolderPath,ItemsInFolder
Run the serach to delete
Search-Mailbox -Identity "Example User" -SearchQuery "kind:meetings" -DeleteContent
and for finishing empty dumpster :
Search-mailbox -identity "username@company.com" -SearchDumpsterOnly -DeleteContent