How about just trying to "get over" feeling that we are "agressive" (or "condescending" or whatever)?
You have given very little information, and almost none since your first post.
It is not even clear if you have followed-up on the Google information, or if you were just looking for the "exact" thing to be explained somehow somewhere, directly, for your case.
I'm not able to view few IEF403I messages in the syslog, except for -
the ones that are generated by Control-M's newday jobs
CTMDAY (Control-M newday procedure)
surprisingly, few jobs submitted by users
SYS1.PARMLIB(MPFLST00) contains "IEF403I JOB START TIME". I checked in a production server and it has the same MPFLST00 entry. I get all IEF403I messages in the production server.
It is not even clear from this what the extent of the problem is. You're "not able to view [a] few" and you seem to say you can see "[surprisingly] few jobs submitted by users".
If you are seeing some
jobs submitted by users, then what is the difference between those that you can see the message for, and those that you can't?
Control-M is a likely part of the equation. What is different in how that is set up where you don't see all the messages, and somewhere where you do see all the messages?
Can you do the Google, and follow-up on the three most likely? Might not give you the answer directly, but might lead you to know more about how the production of the message can be controlled, which might lead you to find the answer itself.
The problem is a "site specific" problem, even "system specific" within your site. There is no "magic answer" anyone can give you ("oh, yes, that must mean you've not...").
If you just don't like being told this in the different ways that you've been told this, so decide not to take any notice, I'm not sure where you're going to go with it.