I might be a little confused right now because I haven't eaten anything for a while, but Mail shouldn't mark a message as read until you click on it. Simply placing your cursor over it shouldn't mark it as read.
Yes, that's what you would expect and that's the way I have it set up on Outlook Express. I've just switched back to the Mac after 10 yrs and am trying to find a way to stop Mail from changing the message from Bold to regular text when just the cursor passes over it. I don't want it to change from Bold until I actually open the message.
Wait, by cursor, do you mean that you are mousing over it without pressing the mouse button, or do you mean that you are moving through the messages by keyboard or otherwise, and that message gets highlighted in blue? If the latter, then this is not a bug. It's the normal operation.
In Outlook, there's a preview pane setting that allows you to select how messages viewed in the preview pane become "read" -- i.e. after a time delay or after they lose focus.
In Mail, I'm not aware of an option like this. However, if the preview pane is turned OFF (drag it all the way down or double click on the separator bar), then the message should not become read unless you actually open it (i.e. in a separate window).
I am actually moving the cursor up and down the list of messages while I take a quick view of them in the preview window. Also, if I go to delete a message then the cursor will end up on a new message and the new message will lose the Bold. This is a problem if you quicly preview messages and come back later to view them. I need to know which ones I have actually opened vs taking a quick preview.
Okay, I think I understand now. It would help if you didn't call that a "cursor," because people will think you mean the mouse pointer... although I guess that's technically a fairly accurate use of the term.
I don't know any way to make it not do this in Mail...sorry.