MacMail Viewing Panel Hidden with Divider Bar Lockup

CT, after I wrote my last response I re-read your answer a few more times, just in case I missed something.

What caught my attention, was the phrase ". . . be patient and do the drag slowly and drag it well into the mail window . . .". I tried this out just to prove to myself that I had not missed something.

Guess what, It actually worked!!

What distracted me from going down the most correct path in interpreting the meaning of your words were, 'be patient', combined with the fact that I tend to find the process of obtaining the correct cursor type, in this situation, slightly annoying.

At the same time I am also grappling with what are the most correct terminologies for me to be effective in describing this situation to other people. This was also a source of frustration for me. The experience of me having written about the issue and having someone, like yourself, respond to me, has greatly helped in this respect.

For people like me, perhaps a better way of describing the situation, might be:-

In the scenarios where the viewing plane has been hidden, and, locked, by way of the divider bar having been moved to the edge of the Mail.app window:- You need to understand that the system requires you to do a noticeably slower than normal drag, of the dividing bar, to at least two thirds of the Email List panel.

However, what I do not understand, is that:- Now that I have re-instated the viewing plane, and, I am able to see the emails, I can now hide and re-instate the viewing plane using a fast drag of the divider bar. That is, I do not need to do another slow drag as described above in order to re-instate the Email View Area.

Could you describe in more detail what was the processes that had occurred here?

CT in any case, Thank you.

When you try to move the divider bar, you have one of two cursors, other than the usual pointer.

By moving the cursor to the bottom (or right) of the divider bar, the vertical (or horizontal) resize cursor as seen below:-

By clicking the primary (left for me) mouse button and while continuing to hold down the button, I am able to do a vertical (or horizontal) resize of the Mail.app window.

After releasing the primary mouse button and nudging the cursor up (or left) by just a touch (this where patience is required), we then get a vertical (or horizontal) divider bar adjustment cursor, as seen below:-

Once again, by clicking the primary (left for me) mouse button and while holding the button down, I try to move the vertical (or horizontal) divider bar away from the edge of the Mail.app window, without success. That is, the divider bar adjustment cursor moves into the interior of the Mail.app window, and even if I continue to hold the cursor steady in that position for at least thirty seconds, the divider bar remains stationary and does not respond by moving accordingly. As shown below:-

You could say the divider bar has been glued to the edge of the Mail.app window, but, I'm calling this 'Divider Bar Lockup'.