As you know Office 365 products and services – such as SharePoint, Exchange Online… – send from time to time email notifications to end-users, such as for document shared, emails in quarantine…
These email notifications have been using Microsoft domains as sender – such as @sharepointonline.com or @planner.com.
Sometimes these emails were incorrectly identified as spam or phishing email by either end-users or mail hygiene solutions (including Exchange Online Protection), and also (if you have implemented the ‘external’ indicator in Exchange Online – see https://t.co/DRZ5eZaukT) will no longer be shown as external.
Well, good news as now Office 365 administrators can now opt-in to use their own custom domains instead of the Microsoft ones for email notifications.
The rollout schedule is as below:
- Targeted release tenant: currently being rollout up to early April
- Standard release tenant: scheduled from early April to mid April
To enable the use of your custom domains for notification emails, connect to your Office 365 administration portal (https://admin.microsoft.com/) and access the Settings\Org settings blade to access the Organization profile tab
Then access the Send email notifications from your domain option to enable and configure the ‘noreply’ address for the email notification
IMPORTANT There may be a need to update DNS records for SPF, MX, DKIM and/or DMARC to ensure emails are being delivered properly, especially if there is relay enabled to on-premises or third party email systems (see https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/mail-flow-best-practices/ for more details); hopefully these records are already properly set as you are using Exchange Online.