To the best of my knowledge, the "all access" that you mention was a bug in IP.Board and no longer exists.
The orginal claim "that an administrator has total access to email and messages" is not factual. That has never been the case with IP.Board at Slotblog, which has been our software platform since July, 2007.
The administrator level power only operates on posts made to Slotblog. Administrators have no involvement in anything else regarding members at any level, their accounts, permissions, PMs, etc. These are root admin functions only and I am the only root admin here at Slotblog.
After we started using the IP.Board platform, a subsequent update added the option for me as root Aamin to log-in as any member (via a button, not using the member's log-in name and password, the latter not being visible even to the root admin) to facilitate troubleshooting and problem resolution with a member's access and account. This has proved to be useful, as it allows me to duplicate remotely exactly what the member is seeing and experiencing.
While logged-in as a member, I certainly could, if I wanted to, go into his PM area and read anything I want. But I simply, as a matter of personal integrity, have never intentionally done so, not a single time. It has happened by mistake less than half a dozen times in over a decade, usually when I was later automatically logged-in as the member I had recently tried to help. In every instance, I backed out immediately once I realized what had happened.
Keep in mind that if you or your PM correspondent adds another person to an existing PM conversation, all of the content in that PM conversation will be visible to the new participant.
There has never been a single confirmed report made to me that a Slotbog member's PMs have been read by an unauthorized person who did not have access to that member's log-in info. If anyone has incontrovertible evidence to the contrary, I would love to see it.
I believe MG's issue concerns a person he was PM'ing who copied parts of their conversation and posted them elsewhere, revealing info he was not pleased to have been made public. There is simply no way for Slotblog to prevent this sort of thing from happening. Even if the platform did not allow for copy and paste of PM content, screenshots would easily get around such a restriction.
As for Slotlog penalizing members who make public Slotblog PM content elsewhere, it is not possible for this forum to enforce or regulate the integrity of its members nor to sit in adjudication when such such regrettable situations occur.
Members should be assured that PMs are Slotblog are about as private as such messages are anywhere, and are certainly much more secure than emails or messages that travel across the internet. Assuming, that is, that the integrity of the root admin is acknowledged and that's your call.