Set-MailboxMessageConfiguration [email protected] –IsReplyAllTheDefaultResponse $false
Get-Mailbox –Resultsize Unlimited | Set-MailboxMessageConfiguration –IsReplyAllTheDefaultResponse $false
Get-Mailbox –Resultsize Unlimited | where {$_.WhenCreated -gt (get-date).adddays(-7)} | Set-MailboxMessageConfiguration –IsReplyAllTheDefaultResponse $false