How to understand where does CPanel get information about mail delivery?

Question

Mail server

There is a mail server, managed via cpanel, which has a wonderful "Delivery Tracking" tab. My task is to get mail delivery tracking data into my program for further manipulations, but I can’t figure out how to do this.
The server was not installed by me, and as I understand it, "through the button next", but there are accesses to it.
Here is the information on the server

spoiler

Версия cPanel 86.0 (build 18)
Версия Apache 2.4.43
Версия PHP 5.6.40
Версия MySQL 10.1.44-MariaDB-cll-lve
Архитектура x86_64
Операционная система linux
Путь к Sendmail /usr/sbin/sendmail
Путь к Perl /usr/bin/perl
Версия Perl 5.16.3
Версия ядра 3.10.0-962.3.2.lve1.5.27.el7.x86_64

At first I thought just to look - maybe this info is somewhere on the server, just reach out, but I did not find anything similar, moreover, I could not find the usr or sbin folders in which I originally planned to find the right one.
I also looked through all the mysql databases that were on the server - and I didn’t find anything suitable there either.

I decided not to fool around and just pull this page and parse it, but the page loads without this basic information, only js & php scripts, and I can’t understand exactly how, and whether it’s possible to execute them in my program ...

Apparently I dug in the wrong direction , because the task seemed to me a little more complicated than I imagined =)
If you have faced a similar task or just know how everything works - tell me how you can pull this information out. suddenly needed - the application will be in C #, all of a sudden there is already something ready (yeah, I hoped).
Most likely, I did not immediately give you some important information, so - ask, I will try to answer in detail.

Answer 1

easiest option: Disposition-Notification-To header

Answer 2

I suspect it's from the sendmail logs.