We are migrating SMTP to CSSMTP due to IBM withdrawing SMTP in z/OS 2.3. The jobname will change from SMTP to CSSMTP, but in order to avoid production job JCL changes, the DEST will remain SMTP. Should the JOBNAME parameter of SMTPPARM remain SMTP to match the DEST, or change to CSSMTP to match the new jobname?
ESP will write the output to JES2 with external writer equal to JOBNAME parameter. In your case if your CSSMTP is set to look for SMTP we recommend to leave JOBNAME set to SMTP and do not change to CSSMTP.