Just a minor thing, not sure if it's intentional or not, but I am mentioning it anyway:

On the posting-screen, if you are able to post attachments, the tab-order is a bit unlogical... When I am writing a message and press TAB, then the preview-button is highlighted. But by pressing TAB more times, the highlight jump down to the preview-buttons below the attachment-section. In my opinion, the tab-order should make it jumt trough all the four buttons on the upper button-row before it jumps down to the buttons below the attachment-section...

Besides that, the section below the attachment-section lacks the "save"-button, is this intentional? To me, having two rows of buttons is in a way illogical, but that's not the main point of this bugreport, the tab-order is the focus