Overriding Sender for Sharing Emails

In SharePoint Server 2013 and above, when a user sends an invite to another user, it sends the invite as that user. This can lead to SMTP servers rejecting mail from a SharePoint server due to lack of send on behalf rights.

Microsoft introduced a fix for SharePoint Server 2016 (and available in 2019 RTM) in November of 2017. KB4011244 allows a farm admin to disable the send on behalf behavior, reverting to the SharePoint Server 2010 and below behavior of sending as the email address configured in the Outgoing Email settings of the farm or Web Application.

This is set via PowerShell on a per-Web Application basis.

$wa = Get-SPWebApplication https://wa
$wa.OutboundMailOverrideEnvelopeSender = $true

Trevor Seward is a Microsoft Office Apps and Services MVP who specializes in SharePoint Server administration, hybrid scenarios, and SharePoint Online. He has been working with SharePoint for 16 years from SharePoint 2003 on up, managing environments with terabytes of content for 150,000+ user organizations. Trevor is an author of Deploying SharePoint 2016 and Deploying SharePoint 2019. You can find him on Twitter and in /r/sharepoint.