Just to play devils advocate here...
Could the PST file mentioned on reddit be from a client computer outlook installed? Meaning that he did not save a PST from the server and the question and answer are accurate.
Outlook saves everything by default on the local computer in a PST file.
Just wondering... Perhaps someone more knowledgeable than I can weigh in.
Locally it's an OST file, I believe. It has to be archived to make a PST file, meaning someone has to do it deliberately.
i think he would have had to archive it due to size thus saved
He said in the thread that he had access to the whole server.
his question on reddit was about altering emails on the server, both in pst file and other types of email data file. he was maintaining the email server (they were running outlook and exchange server). the reddit post is unrelated to this bit of questions, which were certainly not questions directed to him.