Can the administrator of the business delete my emails, send emails from my account without me knowing ? This is a big company so the emailing system is professional

Hi Dave. I'm the HR VP in a startup and I have a frustrating dilemma. Before my last retreat with our branch managers the executive committee agreed that I could keep everything that happened in the meeting confidential, and just present the finished report to them. We had a very successful retreat with a managers pinpointed several problem areas in the company. I reported the information back to the executive committee as agreed.

The executives weren't too happy with the results of the meeting, but I thought that was the end of it. Later I discovered that the two executives who were most unhappy have been pressuring the managers to tell them exactly what happened at the meeting. What the heck?

I complained at the next executive committee meeting but they just laughed at me and told me to "get over it." I feel like they've compromised my credibility with the managers as well as with the executive committee. I'm appalled by their ethics but I'm completely stymied about what to do next. Any suggestions?