The status notification messages that appear in the top center of the reading pain when you perform some action e.g. selecting more than one message, moving a message, deleting a message, etc. obscure the action buttons (Move, Delete, etc.) which requires the user to either A. wait until the message disappears on it's own or B. click to dismiss it if the user wants to use one of the action buttons.

Scenario: I have a bunch of emails in the inbox from a newsletter that I want to select all, mark as read, and then delete. Here are the steps right now:

1. Click the "select all" checkbox at the top of the reading pane
2. Observe the status toast message "X messages selected" appear
3. Either wait or click to dismiss the toast message
4. Click the "More" button and select "Mark as read"
5. Observe the status toast message "X messages marked as read" or something similar
6. Again either wait or click to dismiss the toast message
7. Click the Delete button
8. Yet another toast message, covering the action buttons, appears

This seems like bad UX, as it doubles (or more) the amount of time it takes me to complete my intended goal. I am sure there are additional scenarios to be found where the toast message interrupts the happy path of the user getting the thing done they're trying to get done.

Some screenshots of the above example here:
https://postimg.cc/gallery/zTSgmWz