Relevant Products: Exclaimer Cloud - Signatures for Office 365
Scenario
When an email message is addressed to a distribution group (either in the 'To:' or 'CC:' fields) the message is delivered to the recipient's Junk E-mail folder instead of the Inbox. At the same time, the Return-Path header on the received message is blank and only contains anchor tags.
Note: Additionally, if spam filtering is enabled on the remote messaging system, the message is dropped and delivery reports are suppressed. This occurs because some anti-spam devices might flag messages whose Return-Path field is blank and not let the messages be delivered.
Resolution
- If the group is synchronised to Microsoft 365 from an on-premise Active Directory, set the attribute ReportToOriginator to TRUE (in the properties of the distribution group in the on-premise Active Directory site).
These changes will not take effect until the on-premises Active Directory domain has been synchronised and replicated in Microsoft 365.
Note: For more information, see Microsoft's article: External recipients don't receive email messages that are sent to a distribution group in Exchange Online and senders don't receive nondelivery reports. - If no on-premise Active Directory exists then amend the group properties in Microsoft 365 using Windows PowerShell.
To edit the group properties:
- Open Windows PowerShell and run the following PowerShell command to create a variable that will gather login credentials:
$credential = (get-credential)
When you press [Enter], you will be prompted to enter your Microsoft 365 administrator credentials. - Run the following command:
Import-PSSession (New-PSSession -ConfigurationName Microsoft.Exchange -Credential $Credential -ConnectionURI https://ps.outlook.com/powershell -Authentication Basic -AllowRedirection) -AllowClobber - Then, run the following command:
Get-DistributionGroup | select Identity, ReportToOriginatorEnabled - If the value returned is False, run the command below to change it to True:
Set-DistributionGroup -Identity <groupname> -ReportToOriginatorEnabled $true
Where <groupname> is replaced with the name of the group you wish to change the ReportToOriginator attribute for.