3420227 - If customer uses DEBMAS IDoc to send data from ECC to S/4, the email address will be deleted.

Customer uses a DEBMAS IDoc to synchronize general data from ECC to S/4, which does not even include email address data.

SAP S/4HANA Cloud 2308

Customer uses CPI to transfer IDocs (ECC) into SOAP service payloads and send it to S/4Hana Cloud.
He uses DEBMAS to transfer address data, but DEBMAS doesn't contain email data. Therefore email gets deleted in the target system.

A better approach would be to use SOAP Webservice to send data from ECC to S/4.

KBA , LO-MD-BP-WS , Web Service for Business Partner , How To