Currently the frame for an open mail is locked to being at the right side of the inbox.

Being able to unlock this anchor would be nice, though I don't know if there's a technical limitation to this.

(Classic)

we're looking into it, but hitting a few obstacles for now
the open mail frame interacts differently to most other frames, and likes to cause errors

feel free to test this in the latest BlizzMove alpha release, and report any issues you come across

Thank you, moving the window works as expected.

Scaling and scale reset works as expected with Ctrl.

Reseting position does not seem to work (still works for other windows) with Shift+rightclick (also tried the old Shift-leftclick, and Alt+rightclick).

I am unsure of what is considered a child window where I need to use Alt, I would prefer the Open mail window to use the same UX as other windows. I found the Raid Info-window as child window, and agree with having a separate keybind to detach it.

(3.0.0-alpha2)

in the alpha version, right-click is used for resetting things, left-click only for moving/detaching
and you're right, the raid info window is a good example of a child window; another example is the calendar event frame when you open an event

the open mail frame however isn't a child window, that's because it's not us who decides what a child window is, but blizzard :) (and they have strange logic for such things sometimes..)

we'll look into resetting though

we made some changes that should now be downloadable from twitch client/curse
due to how ElvUI handles the frame, we changed the openmailframe to be a childframe of the main mail frame; so you can detach/reattach the frame with ALT+left/right-click

let us know if there's any other issues with the frame