Send Emails until a Designated Time in Office 365 Exchange Online

#Add extended properties
if ($DeferredSendTime -ne $null) {
    #Identify the extended properties that are used to set the time when the email message is sent.
    $pidTagDeferredSendTime = 16367
    $prDeferredSendTime = New-Object Microsoft.Exchange.WebServices.Data.ExtendedPropertyDefinition(`
                          $pidTagDeferredSendTime,[Microsoft.Exchange.WebServices.Data.MapiPropertyType]::SystemTime)
    #Identify when the email message will be sent and delivered.
    $emailMessage.SetExtendedProperty($prDeferredSendTime,$sendTime)        
}

#Add extended propertiesif ($DeferredSendTime-ne $null) { 
    #Identify the extended properties that are used to set the time when the email message is sent.$pidTagDeferredSendTime = 16367 
    $prDeferredSendTime = New-Object Microsoft.Exchange.WebServices.Data.ExtendedPropertyDefinition(` 
                          $pidTagDeferredSendTime,[Microsoft.Exchange.WebServices.Data.MapiPropertyType]::SystemTime) 
    #Identify when the email message will be sent and delivered.$emailMessage.SetExtendedProperty($prDeferredSendTime,$sendTime)         
}