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3477480 - Message no. XS751 - 421 4.3.2 Service not available


  • Outbound email failed to be sent due to Message no. XS751
  • Following error is recorded in Long text and SAPConnect trace. 

    Message cannot currently be transferred to node SMTP due to connection error.

    Message no. XS751


    The message was processed correctly in the SAP system. Due to a technical fault, the connection to the server mailserver.port could not be established or was interrupted.

    System Response

    The system has marked the message for a resend attempt. The message has not yet been sent.

    Information from external system (if available)

    421 4.3.2 Service not available

    Procedure for the administrator

    Check the connection from the SAP system to node SMTP.



  • SAP Netweaver release independent
  • SAP S/4HANA release independent
  • SAPConnect interface


SAP NetWeaver 7.0 ; SAP NetWeaver 7.1 ; SAP NetWeaver 7.2 ; SAP NetWeaver 7.3 ; SAP NetWeaver 7.4 ; SAP NetWeaver 7.5 ; SAP S/4HANA 1809 ; SAP S/4HANA 1909 ; SAP S/4HANA 2020 ; SAP S/4HANA 2021


Message no. XS751, 421 4.3.2, Service not available, SMTP, SOST, SCOT, SAPConnect , KBA , BC-SRV-COM , Communication Services: Mail, Fax, SMS, Telephony , Problem

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