My in game name is: [Renamed_159867]
I am playing on a Mac version 10.6.8 through Steam
A little while ago the game glitched and I can not open my Mail in game. It says “loading”, but it never loads.
I have already tried logging back out and logging back in, as well as seeing if it would disappear when new mail was received, neither worked.
Quit the game, stop steam, restart steam, log back in
This problem is generally resolved by logging out and back into the game. You mentioned that you did this - but it’s definitely the way to fix it.
As mentioned above, restarting Steam can help as well.