Disabling SharePoint Alerts Temporarily for a Specific SharePoint List

Recently we extended a SharePoint list in our test environment with a few new fields. Users have been complained that they received immediate notifications due to their existing subscriptions on the list. To avoid the same situation in the live system, we decided to temporarily deactivate the alerts for the time of the list field extension. I find a solution for that in this thread, implemented in C#. Although I like C#, for administrative tasks like this one I prefer using PowerShell, so I transformed the code into a few-line script:

$url = ‘http://YourSharePoint/WebSite’
$listTitle = ‘Title of your list’
$targetStatus = [Microsoft.SharePoint.SPAlertStatus]::Off # or [Microsoft.SharePoint.SPAlertStatus]::On

$web = Get-SPWeb $url
$list = $web.Lists[$listTitle]

# to query the current status of the alerts only:
# $web.Alerts | ? { $_.List.ID -eq $list.ID } | % { $_.Status }

$web.Alerts | ? { $_.List.ID -eq $list.ID } | % {
  $_.Status = $targetStatus
  $_.Update()
}

After implementing the changes, you can reactivate the alerts (in this case you should use the value [Microsoft.SharePoint.SPAlertStatus]::On in $targetStatus), however, you should wait a few minutes, as the immediate alerts are sent every 5 minutes by default (see screenshot below). If you turn the alerts on before the next run of the job, your previous change to inactivate the notifications has no effect and the alerts would be sent to the user.

By letting the Immediate Alerts job to have a run after you make the changes in the list, the notification events waiting in the event queue will be purged and not included in the upcoming immediate alerts. They will be however included in the daily and weekly summaries, but that was not an issue in our case.

If you don’t want to wait for the next scheduled run, you can start the job from the UI (see Run Now button above), or via script like this:

Get-SPTimerJob | ? { $_.Name -eq "job-immediate-alerts"} | % { Start-SPTimerJob $_ }