This article concludes our three-part series on SAP® S/4HANA migrations. In Part 1, we looked at industry research highlighting how integration issues drive migration delays. In Part 2, we narrowed the focus to how business messaging must adapt to changing integration standards.
Legacy messaging assumptions create risk
Many organizations assume that existing communication processes and interfaces will transfer seamlessly to S/4HANA cloud solutions. That assumption is risky. With SAP® BTP as the strategic middleware layer, integration patterns fundamentally change. HTTPS‑based APIs and event-driven architectures become the standard. Legacy BC‑SMTP and BC‑RFC connections from the NetWeaver world cannot simply be lifted and shifted, and they are no longer the basis for future certifications as NetWeaver are phased out.
When legacy BC-Con integrations for business messaging are no longer supported, migration projects encounter unexpected obstacles. What appeared to be straightforward transition suddenly requires the redesign of business-critical communication processes under time pressure, putting timelines and project success at risk.
The Solution: End-to-End SAP BTP Integration
Modern enterprises need more than basic connectivity. They require future-ready communication flows that are embedded into their SAP landscape. Our validated integration packages and messaging connectors for SAP BTP extend native SAP capabilities, enabling secure document exchange and transactional messaging directly within SAP processes. By leveraging SAP-certified integration patterns, organizations can avoid custom workarounds and unlock a truly end-to-end experience for email, fax and SMS.
A practical example: Cloud Fax Connetor for S/4HANA via BTP
Fax communication is deeply embedded in SAP landscapes, often through on‑premise fax servers connected to SAP PI/PO and SAPConnect. When moving to S/4HANA and BTP, these legacy integrations quickly become a barrier to automation and digitization. Rather than carrying outdated fax infrastructure into the new architecture, the migration is the ideal moment to modernize and move to a cloud-native fax solution aligned with SAP’s integration strategy on BTP.
Our Cloud Fax Connector for SAP Solutions enables that transition while keeping SAP processes at the core. Built for BTP and SAP ® Integration Suite, it connects directly to S/4HANA Public and Private Cloud Edition and provides a structured migration path from SAPConnect-based scenarios. By consolidating fax and document flows from SAP and non‑SAP applications on BTP, organizations gain centralized monitoring and closer system interaction while reducing project effort through standardized content and less custom development. In line with SAP’s recommended cloud integration direction, the sustainable approach is to move from SAPconnect and on‑premise fax servers to BTP-based integration packages for S/4HANA Cloud and Private Edition instead of further investing in legacy fax infrastructure.
As Jens Koch, Product Manager Messaging at Retarus, explains:
“With our Cloud Fax Connector for SAP Solutions, businesses can seamlessly integrate reliable document exchange into their SAP environments. As an official SAP Build Partner, we are perfectly positioned to support SAP users and ensure that organizations achieve secure and scalable integrations without adding complexity to their migration projects.”
An opportunity to modernize, not replicate
SAP S/4HANA migrations are already a complex task. Rebuilding legacy integrations at the same time only increases risk and delays the project. With modern, cloud‑native messaging solutions designed for SAP S/4HANA and SAP BTP, organizations accelerate project timelines and gain a future‑proof, end‑to‑end foundation for SAP and business messaging.
