Can not turn of notifications (SP 2010)

Question

I'm about to update 300 items in a list that I know lots of users are subscribing to (notification by email on every item update event). I've tried turn this off by using STSADM:

stsadm -o setproperty -url http://[SITE] -pn alerts-enabled -pv false

as well as by using powershell:

$webappurl="http://[SITE]" 
$webapp=Get-SPWebApplication $webappurl 
$webapp.AlertsEnabled=$false 
$webapp.Update() 

The notifications are still sent out by email. What am I doing wrong?

Answer 1

If you make the changes using SPListItem.SystemUpdate() then alerts won't be triggered in the first place: http://msdn.microsoft.com/en-us/library/ms481195.aspx