Replacing SMTP with Microsoft Graph API for Workflow Email Notifications in S/4HANA Public Cloud

[Harshal_91]

Hello SAP Community,

We have a requirement in SAP S/4HANA Public Cloud to replace the standard SMTP-based email sending mechanism with Microsoft Graph API for sending email notifications from Procurement Workflows (PO status updates).

Currently:

• We are using a standard flexible workflow for purchase orders.

• Email notifications are sent via the standard SMTP configuration in Communication Arrangement.

• These emails are triggered by workflow steps (approval, rejection, status update, etc.).

New requirement:

• Due to corporate IT/security policy, SMTP usage is restricted.

• We are required to use Microsoft Graph API (OAuth 2.0) for sending emails instead of SMTP.

We would like to understand:

1. Is it technically possible in S/4HANA Public Cloud to replace standard SMTP with Microsoft Graph API for workflow emails?

2. Is there any standard SAP-supported alternative to SMTP for outbound emails (for example, via SAP BTP services or API-based mail service)?

3. Can workflow email notifications be redirected to:

   • SAP BTP (via API), and

   • then sent using the Microsoft Graph API from BTP?

4. Are there any SAP Notes or official documentation confirming:

   • SMTP is mandatory for workflow emails, or

   • Is API-based email sending supported?

5. Has anyone implemented a similar scenario using

   • SAP Build Process Automation / BTP Integration Suite / custom service with MS Graph API?

Our goal is to:

• Avoid SMTP completely, and

• Use Microsoft Graph API with OAuth authentication for all outbound workflow email notifications.

Any guidance on:

• Supported architecture,

• Limitations in S/4HANA Public Cloud,

• or recommended best practice would be highly appreciated.

Thank you in advance for your support.

Best regards,
Harshal