want emails to slide up from bottom

You have to drag quite a bit before anything happens. Move the cursor to the bottom and when it changes to an arrow pointing ip, click and drag up until the message preview pops up. You have to drag until about the middle of the window.

CuriousCyberCat wrote:

I accidentally dragged down my incoming emails and now there is no display field underneath. The mail user guide says

" If you want messages to slide up from the bottom of the screen instead,

choose Mail > Preferences, click General, then deselect “Prefer opening messages in split view when in full screen.”"

and this does nothing.

3 column view has replaced the classic view —which was removed in macOS Catalina. The only rement of this is "column view" from the Mail>View>Show column view

and if you hide side preview you can regain the up from the bottom preview option.

your Preferences> General >split view when in full screen.”" only controls the stand alone mail window when you double click open a messages compared to splitting the screen to see the stand alone message. Not what you are after.

With Show side preview Grabbing with your mouse the far right border you have to drag the nearly across the before the preview window pops into view— then you can adjust the size of any of the columns in the same way.

If you uncheck show side preview you will have the little dot at the bottom of the window to pull up.

from Mail>View>

ref: https://support.apple.com/guide/mail/read-emails-mlhl7fa3a90d/13.0/mac/10.15

I see from your signature that you're using macOS 10.13 which include the classic layout in Mail (messages list on top and message body on the bottom).

Are you referring to this layout? In case your message body is hidden because it was dragged completely on the bottom, you can revert it by dragging up the dot placed in the middle right on the bottom of the messages list. The mouse pointer should change to an up arrow when hovering it.

Catalina doesn't have Classic layout anymore in Mail. It's impossible to hide the message body to the bottom.

What is possible is to hide the message by dragging the vertical divider between the messages list and the message body to the far right. In this case a left arrow appears just at the edge of the window. Drag it to the left and the body of the message will reappear.

It is correct that Catalina eliminated Classic Mode, but it also introduced a new choice to see the message preview either on the right or at the bottom. This is governed by a new menu item under View. I am not at my mac to check exact wording but you can check or uncheck View->Show Preview on the Right (or something to that effect).

You’re right, Catalina actually still offers the possibility to show the message at the bottom albeit using a different menu name. My “it's impossible to hide the message body to the bottom” was too extreme.