So my boss, for whatever petty reason, has a grudge against me. We recently exchanged an email change where, after I sent a message to a different department about a potential issue in our system, he replied with a slap on the wrist saying I should have talked to my supervisor (I had) and talking to other departments about system issues wasn't within my purview (it was). He sent this email with management CC'd.
I brought up this treatment with my supervisor – who's a really nice guy, one of the best superiors I've ever had – and he said he'd talk to the manager about this. The next day, I logged in to see that the reprimanding email he sent had been recalled and edited to thank me for my dedication to the improvement of the department, rendering my response to it, “what should I have done” nonsensical.
I went though the message details and gathered evidence that that email had been edited, then sent a screenshot to my personal and saved it externally. I then discovered that he'd also recalled and deleted every other interaction we'd ever had.
How can I find the deleted messages or show that they were recalled?