new email window appears almost off screen

Could you try to see if you can reproduce this using the latest test release: Hold down the option key when clicking “Check Now” in the Software Update preferences pane.

I had a similar report where this was caused by the existence of a very small / invisible open composer window. I'm not sure how that happens, but you can try to cycle through the windows of MailMate using the keyboard shortcuts (command + ~ on my keyboard).

Thank you for the suggestions.

I updated to the latest version, and afterwards the compose window would appear fully on screen, but always in the lower left corner (I couldn’t reset its initial position by dragging it to the center and then closing the window, as usual).

So I tried cycling through windows, and indeed it looked like there was one more open window somewhere which didn’t show up on screen. I closed it, and now everything works as expected.

Thank you for your help!