Filter Google Calendar email notifications

As an admin, you can use Calendar Interop to create an email filter rule to hide Google Calendar notifications that are necessary for syncing but don't provide information that your users need.

When a Calendar user invites a Microsoft Outlook user or another calendar user, Calendar sends an email. For recurring events, this can result in multiple emails, some of which your users don't need. Calendar makes it easy to identify these notifications. By using a filter rule, you can keep your users' inboxes uncluttered but their calendars seamlessly synced.

How the rule works

Calendar uses a specific email header ([email protected]) for notifications that are necessary for syncing but include information that's irrelevant to your users. You can set up a rule that filters emails with this message header to your users' trash, or to another folder of your choice.

How to set up the rule

Outlook system administrators can use Microsoft's Powershell to add a filter rule to all users. For details, go to the Microsoft support page. Alternatively, Outlook users can add their own inbox rules. For details, go to Manage Google Calendar invites in other calendar services.

The following sample Powershell script adds a rule that filters all emails with the header [email protected] to the users' archive folder:

$mailboxes = Get-Mailbox

$rule_name = 'Archive Google Calendar Sync Notifications'

$header = '[email protected]'

foreach ($mailbox in $mailboxes) {

  if ( $mailbox.IsResource ) { continue }

  $existing_rules = Get-InboxRule -Mailbox $mailbox.UserPrincipalName

  $already_has_rule = $false

  foreach ($rule in $existing_rules) {

    if ($rule.Name -eq $rule_name) { $already_has_rule = $true }

  }

  if (!$already_has_rule) {

    New-InboxRule -Mailbox $mailbox.UserPrincipalName -Name $rule_name -MoveToFolder "$($mailbox.UserPrincipalName):\Archive" -HeaderContainsWords $header

  }

}