Delete emails from mailbox/es – Exchange 2007

First Grant all the permission to the mailboxes you are to have empty.
Get-Mailbox "target-username" | Add-MailboxPermission -AccessRights FullAccess -User "my-username"


Put the below command in the a file and save it as a .ps1 file - It will delete all the emails from a mailbox catchall without prompting

Add-PSSnapin Microsoft.Exchange.Management.PowerShell.Admin

Get-Mailbox -Identity catchall | Export-Mailbox -DeleteContent  -Confirm:$false

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Put the below command in a file and save it it as a  .bat file and schedule it in windows scheduler
Powershell.exe -command "& {d:\scripts\catchallMailDelete.ps1}"


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Delete everything: (from all Mailboxes)
Get-Mailbox | Export-Mailbox -DeleteContent


Export everything: (and then delete the mails from the mailbox)
Get-Mailbox | Export-Mailbox -PSTfolderPath "c:\temp" -DeleteContent



Delete Emails with a given sender name:
Get-Mailbox | Export-Mailbox -SenderKeywords abc@mydomain.com -DeleteContent