Scenario:
When using Exclaimer Cloud - Signatures for Office 365, messages sent to SharePoint or Office 365 groups are not delivered and the sender receives a Non Delivery Report (NDR).
Cause:
This issue occurs because the sender is not authenticated and so the message is not sent.
Resolution:
As a workaround, sender authentication can be disabled via PowerShell.
- Run PowerShell (as an administrator).
- Run the following command and enter Office 365 Administrator credentials:
$UserCredential = Get-Credential
- Connect to Office 365:
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
- Run the following command:
Import-PSSession $Session
- To obtain a list of SharePoint groups, run the following command:
Get-UnifiedGroup
- Locate the required group and note the Group Name.
- Run the following command, replacing GroupName with the name of the group identified in the previous step:
Set-UnifiedGroup -identity GroupName -RequireSenderAuthenticationEnabled $False