2700110 - Error code XS751 with STARTTLS occurs in transaction SOST during mail sending

• Error message XS751 "Message cannot currently be transferred to node & due to connection error" occurs in transaction SOST when a mail cannot be sent from SAP system.
• The long text contains the "451 TLS required but server does not offer STARTTLS" error message and you can find the HELO keyword instead of EHLO in the level 3 ICM trace which means the standard SMTP protocol is used for the communication.

• SAP Basis 731 006 or higher
• Kernel 721 or higher

XS751, XS 751, STARTTLS, "Message cannot currently be transferred to node & due to connection error", SOST, SMPT, TLS, TLS authentication, server does not offer STARTTLS, 451 TLS required, "Nachricht an Knoten & wg. Verbindungsfehler momentan nicht übergebbar", mail sending error, email, email sending, 451 5.7.3 STARTTLS is required to send mail, , KBA , is required to send mail , 5.7.3 starttls is required , 451 5.7.3 starttls is required to send , 5.7.3 starttls is required to send mail , BC-SRV-COM , Communication Services: Mail, Fax, SMS, Telephony , Problem