SAP SOST Mails Auto Triggered

Issue And Symptoms:

SAP SOST mails auto triggered : SAPCONNECT INT SEND (RSCONN1) was not scheduled in SAP TEST system but still suddenly all the mails were getting sent.
When checked in SOST, we could see mails were sent successfully (672), we need to find out who and how?
Is someone manually triggering SAPCONNECT INT SEND?

How to find it?

Finding SAP SOST mails auto triggered could be tricky !!

As a starting step, from SOST t-code, find out the job number, in our case 000000063517

Now, go to SE16 -> table SOST
Here in OBJNO field, put this job number and execute.

As shown below, CREATOR tab indicates user who has sent the job.

Also we can see :
Recipient year:43 (2018) is changed to 44 (2019: current year) –>(field RECYR) means this USER_A has recently triggered this mail manually or via some job triggering program RSCONN1 .