In Mail.app (8.2 on Yosemite 10.10.3), when I click a message in the list (preview is on the right) and delete it (using keyboard or mouse), it seems quite random as to whether Mail will move the selection to the message above the one I just deleted:
or the one below:
This often results in my deleting a bunch of messages I didn't mean to as I click the top of a list of e.g. build notifications and hit delete multiple times, expecting it to work down through this list, but instead it moves upwards.
I've tried various things - for example I thought it seemed to correlate with my most recent keyboard navigation in the list - if I hit up arrow, then click a mail, then hit delete it would move up, but it's not consistently that either.
Anyone got an explanation, and preferably a solution?
EDIT: here's a video of it happening. I start a sequence by hitting up arrow and pressing delete, then going click-delete repeatedly, and at the end of the video, the selection changes direction: http://youtu.be/hKq7qA3UgaM