I too was unaware of the Command+i trick, but I just tried it and duplicated ryck's results in Safari 7.0. I have thought of some tests you might try to see if they effect your results.
I presume the results are similar on other sites?
Have you tried using another email host such as Google?
Have you tried turning off Safari extensions?
If we knew what it was we were doing, it wouldn't be called research, would it?
