Exclude shared mailboxes from Dynamic Distribution Group

This shows you how to exclude shared mailboxes from a Dynamic Distribution Group in Exchange Online. We will be using Powershell to make sure your shared mailboxes don’t get spam in them.

Exclude Shared Mailboxes

Commands

Connect to O365 in PS:

$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session

Exclude Shared Mailboxes with this filter command:

set-DynamicDistributionGroup -Name "[email protected]" -RecipientFilter {((RecipientType -eq 'UserMailbox') -and -not (RecipientTypeDetailsValue -eq 'SharedMailbox'))}

Conclusion

Afterward, Verify in Exchange Admin Console. You always want to prevent your shared mailboxes from getting spammed in a distribution group. Consequently, I’d highly recommend setting a requirement to send to-these dynamic mailboxes. This will prevent every employee from sending emails to everyone, which will be a bad thing.