https://userapps.support.sap.com/sap/support/knowledge/en/1738232
1738232 - Esker DeliveryWare Servers will not accept messages with no text in the message body |...
Some messages sent from the SAP system to Esker DeliveryWare server fail due to connection errors in SOST (XS816/XS811) When you check the RFC connection to...